Devices and methods for left atrial appendage closure

ABSTRACT

Surgical and percutaneous devices for closing tissue, for example, the left atrial appendage, may have an elongate body with a stiffened proximal portion, a flexible middle portion, a distal portion, a closure element with a loop having a continuous aperture therethrough, and a suture loop. The closure devices may have a malleable member attached to the elongate body that may be configured to retain a curve after a force is applied to the malleable member. System and methods for closing the left atrial appendage may utilize a closure device and a curved guide device, and the closure device and curved guide device may be self-orienting.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/080,410, filed on Mar. 24, 2016, issued as U.S. Pat. No. 9,936,956 onApr. 10, 2018, which claims priority to U.S. Provisional PatentApplication Ser. No. 62/137,738, filed on Mar. 24, 2015, each of whichis hereby incorporated by reference herein in its entirety.

FIELD

This invention relates generally to devices and methods for ligatingtissue, such as the left atrial appendage, using surgically, minimallyinvasive, or intravascular approaches.

BACKGROUND OF THE INVENTION

Atrial fibrillation is a common problem that afflicts millions ofpatients. Atrial fibrillation often results in the formation of athrombus, or clot, in the appendage of the left atrium. This presents aproblem, inasmuch as the thrombus can dislodge and embolize to distantorgans, which may result in adverse events such as a stroke. For thisreason, most patients with atrial fibrillation are treated with one ormore blood thinners to help prevent the formation of a thrombus. Bloodthinners, however, can present health risks of their own, especially inthe elderly. These risks, such as bleeding, often require a user to makesignificant lifestyle changes.

Several methods have been developed to address the potential problem ofthrombus formation in the left atrial appendage. One such methodincludes suturing the left atrial appendage along the base or ostialneck where it joins the atrial chamber. In this way, blood flow into theatrial appendage is cut off, eliminating the risk of thrombus formationtherein. Other methods have also been investigated. These methodsinclude stapling the base of the appendage and filling the appendagewith a space-occupying or occluding member. Stapling is not preferredgiven the fragility of the appendage and its tendency to rupture,whereas occlusion devices may not effectively prevent all blood flowinto the appendage.

Most of these procedures are typically performed through open-heartsurgery; however, some may also be performed using minimally invasivetechniques. Open-heart surgery may limit the availability of theseprocedures to those who are at a particularly high risk, or who areotherwise undergoing an open-heart procedure. In addition, open-heartsurgery requires general anesthesia and has a number of well-knownrisks, which may make it less desirable for some. Therefore, additionaldevices and methods for closing the left atrial appendage usingminimally invasive, intravascular, or a combination of these techniqueswould be desirable in order to avoid the need for opening the chest.

However, at times, the closure of the left atrial appendage is aconcomitant procedure during other cardiac procedures, and performingthe closure during an open-heart procedure may provide benefits incomparison to a minimally invasive procedure. For example, performingthe closure during an open-heart procedure may make it easier forinstruments to access the heart and may allow for better control ormaneuverability of those instruments. Additionally, using an open-heartapproach may provide a better view of the heart and the surroundingtissue during the procedure. Thus, additional devices for use in opensurgical procedures are desirable, especially when those devices offeradditional advantages over standard devices.

BRIEF SUMMARY OF THE INVENTION

Described here are devices, systems, and methods for closing the leftatrial appendage. In general, the devices described here may comprise anelongate body, a closure element, and a suture loop. In some variations,the elongate body may comprise a stiffened proximal portion, a flexiblemiddle portion, and a flexible distal portion. The stiffened proximalportion and the flexible middle portion may comprise cylindricalcross-sections, and the flexible distal portion may comprise a D-shapedcross-section having a height. In some variations, a diameter of thestiffened proximal portion may be greater than a diameter of theflexible middle portion, and a diameter of the flexible middle portionmay be greater than the height of the distal portion. In some instances,the elongate body may be configured to resist rotating when a torsionalforce is applied. The closure element may comprise a loop defining acontinuous aperture therethough and may be at least partially housedwithin the elongate body. In some variations, the stiffened proximalportion may comprise a braided catheter.

In these embodiments, the elongate body may comprise a lumentherethrough and a hypotube disposed within the lumen. In somevariations, the hypotube and the stiffened proximal portion may besimilar lengths. Additionally, the hypotube may comprise a laser cutpattern. In other embodiments, the stiffened proximal portion maycomprise a catheter and a stiffening element. For example, thestiffening element may comprise a braided sheath adhered to the catheterand/or a wire embedded in the catheter. In some variations, the cathetermay comprise a lumen therethrough and the stiffening element maycomprise a polymer tube disposed in the lumen. In these variations, thepolymer tube may be more resistant to bending than the catheter. Inother variations, the catheter may comprise a lumen therethrough and thestiffening element may comprise a stainless steel hypotube disposed inthe lumen. The closure devices may further comprise a laminated jacketon the stiffened proximal portion and the flexible middle portion.

In some variations, the elongate body of the devices described here maycomprise a tapered transition between the flexible middle portion andthe flexible distal portion. In some instances, the elongate body maycomprise a second flexible middle portion between the flexible middleportion and the flexible distal portion, and the second flexible middleportion may comprise a D-shaped cross-section. The length of theflexible middle portion may be between about 1.50 inches (3.81 cm) andabout 2.50 inches (6.35 cm), and in some variations, it may be about1.90 inches (4.83 cm). The length of the second flexible middle portionmay be between about 2.00 inches (5.08 cm) and 3.00 inches (7.62 cm),and in some instances, may be about 2.30 inches (5.84 cm). In someembodiments, the elongate body may further comprise a tapered transitionbetween the second flexible middle portion and the flexible distalportion.

The stiffened proximal portion of the devices described here may have adiameter between about 0.160 inches (4.064 mm) and about 0.169 inches(4.293 mm), and in some instances, the diameter of the stiffenedproximal portion may be about 0.163 inches (4.115 mm). The flexiblemiddle portion of the devices described here may have a diameter ofbetween about 0.156 inches (3.962 mm) and 0.162 inches (4.115 mm), andin some instances, the diameter of the flexible middle portion may beabout 0.160 inches (4.064 mm). The flexible distal portion may have aheight between about 0.094 inches (2.388 mm) and about 0.098 inches(2.489 mm), and in some instances, the height of the flexible distalportion may be about 0.096 inches (2.438 mm). In some variations, thediameter of the stiffened proximal portion may be less than or equal to1.06 times the diameter of the flexible middle portion.

The stiffened proximal portion may have a length between about 12.00inches (30.48 cm) and about 14.00 inches (35.56 cm), and in someinstances, the length of the stiffened proximal portion may be about13.00 inches (33.02 cm). The flexible middle portion may have a lengthbetween about 3.50 inches (8.89 cm) and about 5.0 inches (12.7 cm), andin some instances, the length of the flexible middle portion may beabout 4.20 inches (10.67 cm). The flexible distal portion of the devicesdescribed here may have a length of between about 0.20 inches (5.08 mm)and about 0.40 inches (10.16 mm), and in some instances, the flexibledistal portion may have a length of about 0.25 inches (6.35 mm). In someembodiments, the length of the stiffened proximal portion may be atleast 2.5 times greater than the length of the flexible middle portion.In some variations, the length of the stiffened proximal portion may beat least 3.0 times greater than the length of the flexible middleportion.

The closure devices may further comprise a first lumen and a secondlumen. In some variations, there may be at least about 0.005 inches(0.127 mm) between the first and second lumens. In some embodiments, theclosure devices may also comprise a handle, and rotating the handle 180degrees may cause a distal tip of the elongate body to rotate at least120 degrees, at least 160 degrees, or at least 175 degrees. Moreover, insome variations, the closure device may further comprise a lumenconfigured to retain an end of the suture loop, and the lumen maycomprise a PTFE lining.

In some embodiments, surgical devices for closing the left atrialappendage may comprise an elongate body, a closure element, and amalleable member. The elongate body may comprise a first lumen, a secondlumen, and a third lumen. The closure element may comprise a loopdefining a continuous aperture therethrough. A first end of the closureelement may be slideably disposed in the first lumen, and a second endof the closure element may be fixedly disposed in the second lumen. Themalleable member may be fixedly attached to the elongate body and may beconfigured to retain a curve after a force is applied. In somevariations, applying a force to the malleable member may modify thecurvature of the elongate body. The surgical closure devices may beconfigured to close a left atrial appendage during an open surgicalprocedure, for example, a median sternotomy, a mini sternotomy, athoracotomy, or a thoracoscopy. In some variations, the closure devicesdescribed here may further comprise at least one of a scope, a light, ora camera.

In some variations, the malleable member may be disposed in the thirdlumen. For example, the malleable member may comprise a first end and asecond end, and the first end may be fixedly attached to a proximal endof the third lumen while the second end is fixedly attached to a distalend of the third lumen. In some instances, the malleable member maycomprise an annealed stainless steel wire. The malleable member may alsocomprise a jacket around the elongate body, and the surgical closuredevice may further comprise a pull wire disposed in the third lumen. Thepull wire may be configured to deflect a distal end of the elongatebody. In some variations, the jacket may be annealed stainless steeland/or may comprise a spiral cut pattern.

The closure devices described here may further comprise a handle and atensioning mechanism releasably coupled to the handle. For example, thetensioning mechanism may be rotatably coupled to the handle. In someinstances, the closure device may further comprise a suture loop, andthe tensioning mechanism may be configured to close the suture looparound tissue after it is released from the handle. In some variations,the tensioning mechanism may lock into the handle.

Also described here are systems for closing the left atrial appendage.Any of the closure devices described here may be used with any of thedescribed systems. A system for closing the left atrial appendage maycomprise a closure device and a curved guide device. The closure devicemay comprise a curved elongate body, a closure loop, and a handle, andthe curved elongate body may comprise a stiffened proximal portion and aflexible distal portion. The stiffened proximal portion may comprise afirst outer diameter, and the flexible distal portion may comprise asecond outer diameter. In some variations, the first outer diameter maybe greater than the second outer diameter.

The closure device may comprise a first configuration in which thehandle and the closure loop may be aligned, and a second configurationin which the closure loop is rotated with respect to the handle. Thecurved guide device may comprise a lumen that may be configured toslideably receive the elongate body of the closure device. The curvedguide device and the closure device may comprise a deliveryconfiguration in which the curves of the guide device and the closuredevice have different orientations. In some embodiments, the closuredevice may be configured to remain in the first configuration when theclosure device and the guide device are in the delivery configuration.

Methods for closing the left atrial appendage are also described here.Any of the closure devices described here may be used with any of thedescribed methods. A method for closing the left atrial appendage maycomprise positioning a closure device in a guide device. The closuredevice may comprise an elongate body, a closure loop, and a handle, andthe elongate body may comprise a stiffened proximal portion and aflexible distal portion. The stiffened proximal portion may comprise afirst outer diameter, and the flexible distal portion may comprise asecond outer diameter. In some variations, the first outer diameter maybe greater than the second outer diameter. In some instances, the guidedevice may comprise a lumen that may be configured to slideably receivethe elongate body of the closure device. Moreover, in some embodiments,the closure device and the guide device may be self-orienting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a cross-sectional representation of a heart showingvarious anatomical structures.

FIGS. 2A and 2B depict embodiments of a closure device that may be usedto close the left atrial appendage.

FIG. 3A depicts a distal section of an illustrative variation of aclosure device with a snare loop assembly and FIGS. 3B-3F depictdifferent orientations of the snare loop assembly.

FIG. 4 depicts an illustrative variation of an elongate body suitablefor use with the closure devices described here.

FIGS. 5A and 5B are cross-sectional views of variations of an elongatebody suitable for use with the closure devices here.

FIG. 6A depicts a perspective view and FIGS. 6B and 6D-6F depictcross-sectional views of an embodiment of an elongate body of theclosure devices described here. FIG. 6C depicts a distal end of anembodiment of an elongate body. FIG. 6G depicts a perspective view ofthe embodiment shown in FIG. 6A with a tip.

FIG. 7 illustrates an embodiment of an elongate body with stiffened andflexible portions.

FIGS. 8A-8C depict variations of a transition of an elongate body.

FIG. 9 is an exploded view of an embodiment of an elongate body.

FIGS. 10A and 10B depict variations of an embodiment of a stiffeningelement.

FIGS. 11A and 11B illustrate variations of an embodiment of a closuredevice with a malleable member. FIG. 11C is a cross-sectional view ofthe embodiment of the closure device shown in FIG. 11A.

FIG. 12 provides an embodiment of the closure devices described herewith a visualization tool.

FIG. 13A is a perspective view of an embodiment of the closure devicesdescribed here with a visualization tool. FIG. 13B is a cross-sectionalview of a portion of the embodiment of the closure device shown in FIG.13A.

FIG. 14 depicts an embodiment of a tensioning mechanism.

FIGS. 15A and 15B are perspective and cut-away views, respectively, of aportion of an embodiment of a handle of a closure device.

FIGS. 16A and 16B illustrate an embodiment of a closure device with atensioning mechanism coupled to the handle.

FIGS. 17A-17C depict systems described here having a closure device anda guide device.

FIG. 18 illustrates an embodiment of a closure device comprising acurved distal segment.

FIGS. 19A, 19B, and 19C depict perspective, side, and bottom views,respectively, of a variation of the elongate body of the closure devicesdescribed here.

FIG. 20 illustrates a perspective view of a variation of the elongatebody of the closure devices described here.

DETAILED DESCRIPTION OF THE INVENTION

Described here are devices, systems, and methods for closing tissue, forexample, the left atrial appendage. In instances where the heart is therelevant anatomy, it may be helpful to briefly identify and describe therelevant heart anatomy. FIG. 1 is a cross-sectional view of the heart(100). Shown there is the left atrium (102) and the left ventricle(104). In between the left atrium (102) and the left ventricle (104) isthe mitral valve (also known as the bicuspid valve), which is defined bya pair of mitral valve leaflets (106). The leaflets are connected tochordae tendinae (108) that are connected to papillary muscles (110).The papillary muscles join the ventricular wall (112). The left atrialappendage (114) is shown adjacent to, and is formed from, the wall ofthe left atrium (102).

As can be seen, the left atrial appendage (114) lies within theboundaries of the pericardium (116) and is in close proximity to theventricular wall (112). The left atrial appendage typically has atubular shape that approximates a cone, with a slight narrowing or neckin the plane of the orifice where it joins the left atrium (102). Inpatients with atrial fibrillation, the left atrial appendage (114) isthe most common location for thrombosis formation, which, in time, maydislodge and cause a devastating stroke. Because stroke is the primarycomplication of atrial fibrillation, the left atrial appendage isfrequently excluded from the left atrium in those patients undergoingprocedures to treat atrial fibrillation, and is often removed orexcluded at the time of other surgical procedures, such as mitral valvesurgery, to reduce the risk of a future stroke. The devices and systemsdescribed here help ensure proper closure of the left atrial appendageat the neck or base of the left atrial appendage, along the anatomicostial plane. In this way, exclusion of the entire left atrial appendagefrom systemic circulation may be facilitated.

I. Devices

Described here are closure devices, and methods for closing tissuesusing these closure devices. Generally, the closure devices comprise anelongate body and a snare loop assembly that may extend at leastpartially from the elongate body to capture and hold tissue. The snareloop assembly typically comprises a closure element, for example, asnare, and a suture loop releasably coupled to the snare. The snare loopassembly may be closed around tissue to temporarily or permanentlyclose, ligate, or otherwise tighten tissue, and the suture loop may betightened and released from the snare to hold or otherwise maintain thetissue in the closed configuration.

The closure devices described here may be suitable for advancement tothe left atrial appendage using minimally invasive (e.g., through asmall incision above, beneath, or through the rib cage, through anincision in the costal cartilage or the xiphoid, through a port, throughthe vasculature, and the like.) and surgical (e.g., median sternotomy,mini sternotomy, thoracotomy, thoracoscopy, and the like) approaches.When the closure devices are advanced through confined body spaces, suchas the pericardial space, advancement or manipulation of the snare loopassembly within or through these tight spaces may result in the twistingof one or more sections of the elongate body, which may result in therotation of the snare loop assembly. Accordingly, devices of the currentinvention may resist torsional forces during advancement through thebody. Additionally, in some instances, it may be difficult to access atarget tissue during a procedure because, for example, it may beunderneath or covered by other anatomical structures. Thus, the closuredevices described here may be configured to be shapeable such that theymay retain a curvature in their shafts, which may assist in maneuveringthe closure devices through the body, positioning the closure devices,and accessing and ligating the target tissue. Additionally, the closuredevices described here may comprise elongate bodies with flexiblesections or portions, which may also assist in maneuvering the closuredevices through the body, positioning the closure devices, and accessingand ligating the target tissue.

The closure devices described here may include any suitable elements orcombinations of elements such as those described in U.S. patentapplication Ser. No. 12/752,873, now U.S. Pat. No. 9,198,664, entitled“Tissue Ligation Devices and Controls Therefor” and filed on Apr. 1,2010, the contents of which are incorporated by reference herein in itsentirety. In addition to having an elongate body and a snare loopassembly, the closure devices typically comprise one or more mechanismsfor controlling manipulation and advancement of the elongate body and/orthe snare loop assembly. For example, a handle or other controlmechanism (e.g., a surgical master-slave robotic system) may be used tocontrol and actuate the snare loop assembly through the elongate body.The handle or other control mechanism may change the snare loop assemblybetween a delivery, or “closed,” configuration and a deployed, or“open,” configuration, and vice versa. Placing the snare loop assemblyin a closed configuration may allow for a low-profile advancement of thesnare loop assembly to a target location and/or may allow the snare loopassembly to close around a target tissue. Conversely, placing the snareloop assembly in an open configuration may allow the snare loop assemblyto be placed around one or more target tissues and/or may allow thesnare loop assembly to release one or more target tissues previouslyclosed by the snare loop assembly.

In use, a distal end of an elongate body may be advanced into the bodytoward a target tissue (e.g., the left atrial appendage). Duringadvancement, the snare loop assembly may be in a closed configuration tohelp prevent the snare loop assembly from snagging or catching on tissueor other obstructions. Once the distal end of the elongate body hasreached a location at or near the target tissue, the snare loop assemblymay be opened to a deployed configuration. The snare loop assembly maythen be advanced, moved, or otherwise manipulated to encircle at least aportion of the target tissue. The snare loop assembly may then be closedaround the encircled tissue to close, ligate, or otherwise restrict thetarget tissue. The snare loop assembly may be re-opened, repositioned,and re-closed as necessary. In some instances, a suture loop or otherrestricting device may be tightened and released from the closure deviceto maintain the target tissue in a closed fashion. To remove the closuredevice from the body, the snare loop assembly may again be opened torelease the target tissue (the suture loop or other restricting devicemay remain in place) such that the snare loop assembly and the elongatebody may be withdrawn. Once the target tissue is released, the snareloop assembly may be closed to facilitate a low-profile withdrawal. Invariations where the closure device comprises a tensioning device ormechanism, the tensioning device or mechanism may be used to release thesuture loop from the snare loop assembly and/or tighten the suture loop.

The closure devices may contain one or more additional features, as willbe described in more detail below. In some variations, the elongate bodymay comprise multiple sections which may have one or more definingcharacteristics, for example, a particular stiffness, cross-sectionalshape, diameter, etc. Utilizing a closure device with multiple sectionsmay allow a user to more easily maneuver the device through the body andmay provide more control over the device during a closure procedure. Insome instances, the elongate body may be shapeable, meaning that theelongate body may be manipulated (e.g., bent) and may retain themanipulated shape until a user or other applied force (e.g., from tissuewithin the body) further modifies it. These and other features will bedescribed in more detail below. It should be appreciated that theclosure devices described here may comprise any combination of thesefeatures and the other features described below.

FIGS. 2A and 2B depict exemplary devices (200A, 200B) that may be usedto close the left atrial appendage. Shown there are a snare loopassembly (202A, 202B), an elongate body (204A, 204B), and a handle(206A, 206B). As noted above, the handle (206A, 206B) may be used tocontrol and actuate the snare loop assembly (202A, 202B) through theelongate body (204A, 204B) in order to move the snare loop assembly(202A, 202B) between a closed configuration and an open configuration,and vice versa. In some variations, and as shown in FIG. 2B, the handlemay comprise a suture tensioning element (210) that may deploy and/ortighten a suture loop. When in an open configuration, the snare loopassembly (202A, 202B) and the elongate body (204A, 204B) may form acontinuous loop (208A, 208B) (e.g., such that the snare loop assembly(202A, 202B) and the elongate body (204A, 204B) may fully encircletissue placed in the loop (208A, 208B)). When moved from the openconfiguration to the closed configuration, the size of the loop (208A,208B) may be reduced as some or all of the snare loop assembly (202A,202B) is withdrawn into the elongate body (204A, 204B). Individualcomponents of the closure devices described here are described in moredetail below.

Snare Loop Assembly

As mentioned above, the snare loop assemblies of the closure devicesdescribed here may be used to temporarily close or restrict one or moretarget tissues. Generally, the snare loop assembly comprises a closureelement, e.g., a snare, and a suture loop releasably attached to theclosure element. In some variations, the snare loop assembly maycomprise a retention member at least temporarily connecting the closureelement and the suture loop. FIG. 3A shows a distal section of anillustrative variation of a closure device (300) comprising a snare loopassembly (302), an elongate body (304), and a tip (306) coupled to theelongate body (304). As shown there, the snare loop assembly (302) maycomprise a snare (308), a suture loop (310), and a retention member(312), and may be disposed relative to the elongate body (304) such thatat least a portion of the snare loop assembly (302) extends from theelongate body (304) (e.g., via tip (306)). The snare loop assembly (302)is shown in FIG. 3A in an open configuration, and the portion of thesnare loop assembly (302) extending out of elongate body (304) may forma loop (314) having an aperture (316) therethrough. The loop (314) andthe corresponding aperture (316) may be defined by one or morecomponents of the snare loop assembly (302) (e.g., the snare) and may besuitable for encircling tissue such as the left atrial appendage.Generally, the snare (308) may be used to open and close the snare loopassembly (302). In some instances, the retention member (312) may beconfigured to releasably couple the suture loop (310) and the snare(308) and may be configured to release the suture loop (310) from thesnare loop assembly (302) upon application of a sufficient force tosuture loop (310).

In variations of snare loop assemblies comprising a snare, the snare maybe at least partially moveable to change a snare loop assembly betweenopen and closed configurations. Generally, a portion of the snare may behoused in the elongate body, and another portion of the snare may extendoutside of the distal end of the elongate body to at least partiallydefine the loop and aperture of the snare loop assembly. In somevariations, one end of the snare may be fixed relative to one or moreportions of the closure device, while the other end may be advanced orretracted through the elongate body. Movement of the free end of thesnare may change the amount of the snare loop assembly that is disposedoutside of elongate body, and thus may change the size (e.g., diameter,circumference, area, etc.) of the loop and the aperture defined thereby.Specifically, advancement of the snare through the elongate body mayincrease the size of the loop and aperture of the snare loop assembly,while retraction of the snare may decrease the size of the loop andaperture of the snare loop assembly. The free end of the snare may bemanipulated in any suitable manner. In some variations, the snare may beattached directly to one or more portions of the handle. In othervariations, a hypotube, rod, or other rigid structure may be attached tothe free end of the snare. This structure may in turn be moved by thehandle, which may help facilitate advancement or withdrawal of the snarethrough the elongate body.

The closure elements or snares described here may be made of anysuitable material or combination of materials. For example, in somevariations, the snare may be made from a shape-memory material, such asa shape-memory alloy (e.g., a nickel titanium alloy, etc.), or may bemade from stainless steel, polyester, nylon, polyethylene,polypropylene, combinations thereof, and the like. In variations wherethe snare is made from a shape-memory material, the snare may beconfigured to take on a particular shape or configuration when the snareloop assembly is placed in an open configuration, but may still be atleast partially withdrawn into the elongate body to place the snare loopassembly in a closed configuration. For example, the snare may form agenerally circular, teardrop-shaped, oval or ellipsoid, or triangularloop when the snare loop assembly is placed in an open configuration.

Furthermore, in some variations, the snare loop assembly may be angledrelative to the elongate body. As shown in FIGS. 3A and 3B, the snareloop assembly (302) is in a plane that is approximately perpendicular tothe distal end of the elongate body (304), however, the plane of thesnare loop assembly (302) may be varied over a wide range of angles (α),as depicted in FIGS. 3B-3F. For example, the angle (α) formed betweenthe plane of the snare loop assembly (302) and the distal end of theelongate body (304) may be between about 5 degrees and about 85 degrees(FIG. 3C), may be about 90 degrees (FIGS. 3A and 3B), may be betweenabout 95 degrees and about 175 degrees (FIG. 3D), may be about 180degrees (FIG. 3E), or may be between about 185 degrees and about 270degrees (FIG. 3F). In some variations, the angle (α) formed between theplane of the snare loop assembly (302) and the distal end of theelongate body (302) may be between about 5 degrees and about 45 degrees.Angling the snare relative to the elongate body may aid the snare incapturing tissue, as angling may better position the snare relative totissue as the closure device is moved in the body.

Suture Loop

The snare loop assemblies described here may also comprise a suture loopfor maintaining tissue in a closed manner. Generally, the suture loopmay be releasably attached to the snare, for example, via a retentionmember, as will be described in more detail below. Furthermore, thesuture loop may comprise a suture knot, but need not. This suture knotmay be any suitable knot, including, but not limited to, a slip knot(e.g., a one-way slip knot) or a Meltzer knot. In some variations, atleast a portion of the knot may be held within the tip of the elongatebody. In other variations, the suture knot at least partially extendsfrom the tip of the elongate body or may be positioned outside of thetip and may be temporarily held in fixed relation to the elongate body.When the suture loop comprises a suture knot, the suture loop maycomprise a loop portion, a suture knot, and a tail extending from thesuture knot. The suture tail may be pulled through the suture knot toreduce the diameter of the loop portion.

In variations where the suture loop comprises a slip knot, suture may beadvanced or withdrawn through the slip knot to change the size of thesuture loop. In instances where the suture knot is held within oragainst a tip of the elongate body, the suture knot may not move whilethe size of the suture loop is changed. This may help prevent theclosure device from damaging tissue. In some variations, the suture loopmay comprise a unidirectional locking structure. In these variations,the unidirectional locking structure may be any structure capable ofbeing advanced along the suture in one direction but resisting movementin a second direction. In these variations, the locking structure may beadvanced over a portion of the suture loop to help lock a suture knot inplace. For example, in some variations, the unidirectional lockingstructure may comprise a bead or a mechanical structure that is placedat least partially around the suture. In these variations, the bead maycomprise one or more teeth or projections that allow the bead to beadvanced along the suture in one direction, but prevent or resistmovement in the opposite direction. The locking structure may beadvanced via one of the closure devices described here, or it may beadvanced by a separate device after the suture loop has been releasedfrom the closure device.

The suture loop may be made from any suitable material useful in tissueexclusion or closure. For example, it may be made of a biodegradablematerial (e.g., polylactic acid, polyglycolic acid,polylactic-co-glycolic acid, etc.), or it may be made of anon-biodegradable material (e.g., metal, steel, polyester, nylon,propylene, silk, combinations thereof, etc.).

Retention Member

When the snare loop assemblies described here comprise a retentionmember releasably coupling the snare and the suture loop, the retentionmember may be any suitable member, such as dual-lumen tubing. In somevariations, one lumen may have a slit, perforation, or other openingalong its length, which may allow the suture to pass therethrough whenit is ready to be deployed. The slit need not extend or be continuousalong the entire length of the retention member. In some variations, theslit may have prongs or arms along its length to help capture and retainthe suture in the retention member. In other variations, the slit may becovered at spaced-apart locations with a biodegradable polymer, whichmay temporarily tack or hold down the suture. Of course, in still othervariations, the retention member does not comprise a slit, and insteadcomprises some other type of retention mechanism, such as the prongs ortacks described just above. In yet other variations, there are no slitsor openings in the retention member, and the suture loop is releasedupon removing or withdrawing the retention member.

Elongate Body

As mentioned briefly above, the closure devices described here generallycomprise an elongate body. The elongate body may connect the distal endof the snare loop assembly and the handle or actuating mechanism whilestill allowing for control of the snare loop assembly through theelongate body. Specifically, at least a portion of some of the snareloop assembly components may be housed within the elongate body and maybe connected to the handle through the elongate body. In somevariations, portions of the elongate body may be flexible, which mayhelp facilitate movement and navigation of the elongate body throughtissue. The elongate body may comprise various sections or portions withdifferent characteristics, for example, different diameters,cross-sectional shapes, stiffnesses, materials, and the like, which mayincrease the steerability and maneuverability of the closure device.

Geometry

FIG. 4 shows an illustrative variation of an elongate body suitable foruse with the closure devices described here. Shown there is an elongatebody (400) attached to a handle (402). The elongate body (400) maycomprise a curved segment (406), a first lumen (408), a second lumen(410), and a third lumen (412). The curved segment (406) may assist inguiding the distal end of the closure device to the target tissue, forexample, the base of the left atrial appendage, and may have an angleand radius selected to facilitate appropriate positioning at the targettissue, for example, within the pericardial space. For example, FIG. 18depicts a variation of an elongate body (1800) comprising a proximalstraight segment (1802), a distal curved segment (1804) with a radius(1810) and an angle (1812), a handle (1806), and an illustrative loop(1808) (e.g., a snare loop, a suture loop, a snare loop assembly). Theangle (1812) may be measured from a plane perpendicular to thelongitudinal axis of the proximal straight segment (1802) to the planeformed by the loop (1808). In some variations, the angle (1812) may beabout 20 degrees to about 100 degrees and the radius (1810) may be about2.00 inches (5.08 cm) to about 6.00 inches (15.24 cm). In someinstances, the angle (1812) may be about 45 degrees to about 90 degreesand the radius (1810) may be about 2.00 inches (5.08 cm) to about 4.00inches (10.16 cm). In some variations, the angle (1812) may be about 86degrees to about 88 degrees and the radius (1810) may be about 3.10inches (7.87 cm) to 3.40 inches (8.64 cm). In some of these variations,the angle (1812) may be about 87 degrees and the radius may be about3.30 inches (8.38 cm). In other variations, the angle (1812) may bebetween about 84 degrees and 86 degrees, and the radius (1810) may bebetween about 2.60 inches (6.60 cm) and about 2.90 inches (7.37 cm). Insome of these variations, the angle (1812) may be about 85 degrees andthe radius may be about 2.8 inches (7.11 cm). As mentioned above, insome instances, the configuration of the distal curved segment (1804),including the angle (1812) and radius (1810), may facilitate positioningthe closure device relative to the target tissue. However, otherfeatures described herein, which may affect the flexibility andtorqueability of the elongate body (e.g., cross-sectional shape,cross-sectional diameter/height, number of flexible portions, proximalstiffening elements), may also contribute to the ability to advance andposition the closure device. Thus, the features described herein thatmay affect the flexibility and torqueability of the elongate body maydetermine what angle (1812) and radius (1810) may be most desirable fora particular procedure.

Turning back to FIG. 4, in some variations, the closure device maycomprise one or more mechanisms that may act or function to change theshape of the elongate body (400), as will be described in more detailbelow. In instances where the elongate body (400) comprises one or morecurved segments (406), a tube, mandrel, or other straightening mechanism(not shown) may be used to temporarily straighten the elongate body. Theelongate body may be made of any suitable material, for example, one ormore polymers (e.g., polyether block amide, polyethylene, silicone,polyvinyl chloride, latex, polyurethane, PTFE, nylon, and the like).While shown in FIG. 4 as having a single curved segment (406), theelongate body (400) may not have any curved segments, or it may havemultiple curved segments along its length.

The elongate body may comprise any suitable length, and the length ofthe elongate body may vary depending on the type of procedure beingperformed. For example, the length of the elongate body may generally bebetween about 6 inches (15.24 cm) and about 19 inches (48.26 cm). Asused herein, “about” means±5%. During a minimally invasive procedure,the elongate body may have to travel a further distance through the bodyto reach a target tissue than when the device is used in a surgicalprocedure. Thus, it may be desirable to use a longer elongate body whenusing the device in a minimally invasive procedure and a shorterelongate body when using the device in a surgical procedure. Forinstance, it may be desirable to use an elongate body with a lengthbetween about 15 inches (38.10 cm) and about 18 inches (45.72 cm) duringa minimally invasive procedure and an elongate body with a lengthbetween about 6 inches (15.24 cm) and about 12 inches (30.48 cm) duringa surgical procedure. In some instances, it may be desirable to use anelongate body with a length between about 15.5 inches (39.37 cm) andabout 16.5 inches (41.91 cm) during a minimally invasive procedure andan elongate body with a length between about 9.5 inches (24.13 cm) andabout 10.5 inches (26.67 cm) during a surgical procedure.

Moreover, the elongate body may comprise any suitable cross-sectionalshape, for example, circular (as depicted in FIG. 4), oval, D-shaped,triangular, and the like. In some embodiments, the cross-sectional shapeof the elongate body may vary along its length. In some variations, theelongate body may be described as having multiple portions, each portioncorresponding to a specific cross-sectional shape. For example, theelongate body may comprise a proximal portion with a firstcross-sectional shape (e.g., circular) and a distal portion with asecond cross-sectional shape (e.g., D-shaped). Of course, the elongatebody may comprise any suitable number of portions, e.g., two, three, orfour portions, and the length of each portion may be the same as ordifferent from the other portions. In some variations, a tip (404) maybe coupled to the elongate body.

The elongate body may also comprise any suitable outer diameter, and, insome instances, the outer diameter of the elongate body may also varyalong its length. Typically, the outer diameter of the elongate body maybe between about 0.120 inches (3.048 mm) and about 0.220 inches (5.588mm); however, it may be desirable to restrict the largest outer diameterof the elongate body so that it can fit through a guide device having aspecific diameter. For example, in instances in which the closure deviceis used during a minimally invasive procedure, it may be desirable tolimit the outer diameter of the elongate body such that it may fitthrough 13-French percutaneous tubing.

As mentioned above, and depicted in FIG. 4, the elongate body maycomprise multiple portions with different diameters. For example, theelongate body (400) may comprise a proximal portion (414) with a firstdiameter and a distal portion (416) with a second diameter. As shown inFIG. 4, the first diameter may be larger than the second diameter;however, this need not be the case. In some instances, the elongate bodymay comprise at least two, three, four, or five portions with differentdiameters. In some variations, the portions of the elongate body havingdifferent diameters may correspond to (i.e., may have the same lengthand be located at the same location along the length of the elongatebody) the portions described above having different cross-sectionalshapes. Of course, this need not be the case. Moreover, in instances inwhich the cross-section is D-shaped, a height will be referred toinstead of a diameter. In some embodiments, the height may be largerthan the diameter of one or more other portions, whereas in otherembodiments the height may be smaller than the diameter of the otherportions of the elongate body.

The elongate body may further comprise one or more transitionsconnecting the portions of the elongate body comprising differentdiameters or different cross-sectional shapes. These transitions mayhave any suitable length. In some variations, the transitions mayconnect two portions of the elongate body that have both differentdiameters (or heights) and different cross-sectional shapes. Turningback to FIG. 4, in the embodiment shown there, the elongate body (400)comprises a transition (418) that connects the proximal portion (414)(having the first diameter) and the distal portion (416) (having thesecond smaller diameter). While the transition (418) is depicted in FIG.4 as beveled or tapered along only a portion of the circumference of theelongate body (i.e., the underside of the elongate body), it should beappreciated that it may be beveled or tapered along any portion of oralong all of the circumference of the elongate body. Moreover, in somevariations, the transition (418) may not be beveled or tapered at alland may instead create a shoulder or a ledge (using right angles or thelike, as will be described below). In some instances, the diameter orheight of the elongate body may change gradually along its length suchthat a discrete transition region is not apparent.

Lumens

The elongate bodies described here may have any suitable number oflumens. As used herein, “lumen” may refer to any bore or passagewayextending through a length of the elongate body or other portion of theclosure device (e.g., through a handle). It should be appreciated that alumen need not be entirely enclosed (i.e., the lumen may comprise one ormore slots, slits, gaps, or other openings along some or all of thelength of the lumen). The elongate body may comprise one, two, three,four, or five or more lumens. Some or all of the lumens may extendentirely through the elongate body (i.e., from the proximal end of theelongate body to the distal end of the elongate body). Other lumens maypass through only a portion of the elongate body (e.g., from one end toan intermediate point along the elongate body, or between twointermediate points along the elongate body).

The various components of the snare loop assembly may be housed withinany lumen or lumens of the elongate body. For example, in somevariations, all of the components of the snare loop assembly may behoused in a single lumen. In other variations, different portions of thesnare loop assembly may be at least partially housed in differentlumens. For example, the free end of the suture loop may pass to thehandle through a first lumen, while the free end of the snare may passto the handle through a second lumen. In some variations, there may beexcess suture housed within the elongate body, and this excess suturemay be housed in any suitable lumen. For example, the excess suture maybe held in the same lumen as the free end of the suture loop, in thesame lumen as the free end of the snare, or in an altogether differentlumen.

FIGS. 5A and 5B are cross-sectional views depicting the lumenconfigurations of illustrative elongate bodies. FIG. 5A depicts anexemplary elongate body (500) comprising a first lumen (502), a secondlumen (504), and a third lumen (506). In this embodiment, the firstlumen (502) may house the free or moving leg of the snare, and a portionof the suture loop and excess suture if necessary; the second lumen(504) may house the fixed leg of the snare and a portion of the sutureloop; and the third lumen (506) may house a guide device, for example, aguide wire. As is depicted in FIG. 5A, the lumens may have differentdiameters and cross-sectional shapes. For example, referring to theembodiment depicted in FIG. 5A, the first lumen (502) and the thirdlumen (506) may be circular, whereas the second lumen (504) may be oval.The first lumen (502) may have a larger diameter than the semi-majoraxis of the second lumen (504), and the semi-major axis of the secondlumen (504) may be larger than the diameter of the third lumen (506). Insome instances, the diameter of the first lumen (502) may be betweenabout 0.07 inches (1.78 mm) and about 0.08 inches (2.03 mm), thesemi-major axis of the second lumen (504) may be between about 0.05inches (1.27 mm) and about 0.06 inches (1.52 mm), and the diameter ofthe third lumen may be between about 0.04 inches (1.02 mm) and 0.05inches (1.27 mm).

FIG. 5B depicts another variation of the elongate body (500) comprisingfour lumens (502, 504, 506, 508). In this embodiment, the second lumen(504) may house a portion of the suture, and the fourth lumen (508) mayhouse a leg of the snare. In some variations, the fourth lumen (508) mayalso house a lockwire configured to anchor a leg of the snare to theelongate body (500). In some embodiments, the snare may be releasable,and the lockwire may optionally release the leg of the snare.Additionally, the second and third lumens (504, 506) may have the sameor very similar diameters, which may be greater than the diameter of thefourth lumen (508). In this variation, the diameter of the fourth lumenmay be between about 0.02 inches (0.508 mm) and about 0.03 inches (0.762mm). While all the lumens are depicted as circular, this need not be thecase, and the lumens may have any suitable shape.

While the lumens are depicted in specified locations within the elongatebody, the lumens may be positioned in any location within the elongatebody (i.e., their centers may be moved and their locations shifted);however, it may be desirable to maintain a minimum wall thicknessbetween the lumens to prevent breakthrough. For example, in somevariations, it may be necessary to heat the elongate body after it isextruded or otherwise manufactured to attach, insert, or bond stiffeningor other elements to the closure device, as will be described in moredetail below. Heating the elongate body may cause the lumens to shiftlocations or change in size. In some instances, a portion of thematerial separating the two lumens may sever such that the lumensconverge or otherwise come together forming one lumen instead of two. Inorder to decrease the likelihood of this breakthrough, it may bedesirable to maintain a minimum distance between the lumens duringextrusion and/or heating. Additionally, as described above, in somevariations, a portion of the elongate body may comprise a D-shapedcross-section, which may be created by cutting, shaving, skiving, orotherwise removing a portion of the elongate body. In these variations,maintaining a minimum wall thickness between the lumens may prevent thelumens from shifting during heating and becoming severed when theelongate body is cut to create the D-shape. Accordingly, in somevariations, it may be desirable to maintain at least about a 0.005 inch(0.127 mm) wall thickness between the lumens.

Additionally, in some variations, the lumens may comprise a lining or acoating designed to reduce the frictional forces between the internalsurface of the lumens and the components housed within them. The smallsize of the lumens, their relative locations, the materials used, andthe precision required to fabricate the elongate body may result inmanufacturing variations (e.g., different frictional characteristicsinside the lumens) between different lots and/or differentmanufacturers. These variations may lead to an inconsistent userexperience and may result in frustration with the closure device and/orimproper usage. For example, if the frictional forces between theinternal surface of the suture lumen and the suture vary, the user maybe required to apply different amounts of force to tighten the sutureeach time the device is used. This may result in over or undertightening of the suture around the tissue. Accordingly, in someembodiments, the suture lumen may comprise a friction-reducing lining orcoating (e.g., a polytetrafluoroethylene (PTFE)). It may be desirable toinclude a friction-reducing lining in any and/or all of the lumens ofthe elongate body, as doing so may result in a more consistent andpredictable user experience.

Turning back now to features of the elongate body, FIG. 6A depictsanother variation of an elongate body (600) comprising a collar (602), afirst portion (604), a first transition (606), a second portion (608), asecond transition (610), a third portion (612), and markers (614). FIG.6G depicts the variation of the elongate body (600) shown in FIG. 6Awith a tip (603) coupled to the distal end of the elongate body (600).As mentioned above, each portion of the elongate body may have differentcharacteristics, for example, each portion may correspond to aparticular cross-sectional shape, diameter or height, and/or stiffness.In the embodiment depicted in FIG. 6A, each portion of the elongate bodycorresponds to a particular cross-sectional shape or diameter of theelongate body and, in some instances, to both a particularcross-sectional shape and a particular diameter. The first transition(606) connects the first portion (604) to the second portion (608), andthe second transition (610) connects the second portion (608) to thethird portion (612). It should be appreciated that while the elongatebody (600) is depicted with three portions and two transitions, it couldhave any suitable number of portions (e.g., two, three, four, five, six,seven, or eight) and transitions (e.g., one, two, three, four, five,six, or seven).

FIGS. 6D-6F depict cross-sectional views of the first, second, and thirdportions (604, 608, 612) along lines DD, EE, and FF of FIG. 6A,respectively. As shown in FIGS. 6D-6F, the first portion (604) comprisesa cylindrical cross-section with a diameter (605), the second portion(608) comprises a D-shaped cross-section with a first height (609), andthe third portion (612) comprises a D-shaped cross-section with a secondheight (611). In this variation, the diameter (605) of the first portion(604) may be greater than the first and second heights (609, 611).Moreover, as depicted here, the first height (609) may be greater thanthe second height (611), however, in some instances the second height(611) may be greater than the first height (609).

FIG. 6B depicts a cross-sectional view of the elongate body (600)comprising a first lumen (616), a second lumen (618), a third lumen(620), a fourth lumen (622), a first skive line (624), and a secondskive line (626). The first, second, third, and fourth lumens (616, 618,620, 622) may be analogous to the first, second, third, and fourthlumens (502, 504, 506, 508) of FIG. 5B, described in more detail above.As mentioned above and depicted in FIGS. 6E and 6F, in some instances,the elongate body may comprise a D-shaped cross-sectional shape. Inorder to fabricate an elongate body with a D-shaped cross-sectionalshape, a portion of the elongate body may be cut or otherwise removed.In this embodiment, the first and second skive lines (624, 626) indicatewhere to cut the elongate body (i.e., at what height) to remove a bottomsection of it to create a portion or portions of the elongate bodycomprising a D-shaped cross-sectional shape. Cutting the elongate body(600) at the first and second skive lines (624, 626) yields an elongatebody (600) with the cross-sectional shapes depicted in FIGS. 6F and 6E,respectively. Thus, the first and second skive lines (624, 626) maycorrespond to the heights for the third and second portions (612, 608)of the elongate body (600), respectively. In removing the bottom sectionof the elongate body (600), a section of the elongate body forming allor part of the third lumen (620) may be removed. For example, when theelongate body (600) is cut at the first skive line (624), all of thethird lumen (620) may be removed (as shown in FIG. 6F), and when theelongate body is cut at the second skive line (626), only a portion ofthe third lumen (620) may be removed (as shown in FIG. 6E) such that theelongate body (600) comprises a lumen in the form of a groove, as can beseen in FIG. 6C.

In some variations (e.g., when using the device in a minimally invasiveprocedure), cutting the elongate body along the first and/or secondskive lines may allow the device to more easily access the neck of theleft atrial appendage for closure. The devices described here may beadvanced to the LAA along a guide wire housed in a lumen (e.g., thethird lumen (620)) of the elongate body (600). In some embodiments, thedevices may be used with a set of guide wires (e.g., a transeptal guidewire and a pericardial guide wire) comprising alignment members (e.g.,magnets, interconnecting members, radiopaque or echogenic markers, andthe like) on their distal ends that align the guide wires across tissue(e.g., the LAA). A closure device may be advanced pericardially to theLAA along the pericardial guide wire until it reaches the distal tip ofthe LAA. In order to advance the snare loop assembly or closure looparound the LAA and to its neck for closure, the distal tip of theelongate body, from which the closure loop extends, may need to beadvanced past the distal tip of the LAA while the alignment membersremain engaged or otherwise aligned. Removing the bottom section of adistal portion of the elongate body (600) and part or all of the lumenhousing the guide wire (e.g., the third lumen (620)) may allow thedistal end of the elongate body (600) and the closure loop to travelpast the distal tip of the guide wire (and the alignment member attachedthereto) and the LAA, to the neck of the LAA, while the guide wireremains in the remaining (proximal) portion of the guide wire lumen.After the suture loop is deployed, the elongate body (600) may then beremoved from the body of a patient using the same pericardial guide wirethat it was advanced along. Thus, the guide wire need not be removed orrepositioned during a procedure to allow the distal end of the elongatebody, and the closure loop attached thereto, to access the neck of theLAA for closure.

FIG. 6C is a perspective view of a distal end of the elongate body (600)and depicts the first and second transitions (606, 610) and the secondand third portions (608, 612) of the elongate body (600). The first andsecond transitions (606, 610) may comprise an angled, ramped, tapered,and/or beveled bottom surface (628, 630), which may prevent the elongatebody (600) from kinking or getting caught on tissue when advancingthrough the body. As depicted in FIG. 6G, in some embodiments, the thirdportion (612) may have a tip (603) covering it. The tip (603) may bedesigned to align with the distal edge of the second transition (610)such that the tip is flush with the distal edge of the second transition(610) (e.g., the height of the third portion (612) may be the same asthe height of the distal edge of the second transition (610), and theremay be no space or gap between the tip (603) and the distal edge of thesecond transition (610)). The tip may be made of any suitable material,and in some variations, may be a rigid polymer.

In some instances, it may be desirable to utilize an elongate bodycomprising additional portions, which may further vary the bendingcharacteristics of the elongate body along its length. For example, insome instances, the orientation, shape, and/or location of a targettissue may make it difficult to access and/or ligate. Accordingly, insome circumstances, it may be desirable for a longer portion of theelongate body of the closure devices described here to be flexible, asthis may facilitate access to and ligation of hard to reach tissues.This may be especially useful in variations of the closure devicesdescribed here comprising stiffened proximal portions because, while thestiffened proximal portions may assist with the torqueability of theclosure devices, they may, in some instances, decrease the flexibilityof the elongate body. Therefore, utilizing an elongate body comprisingadditional portions designed to increase bending flexibility may resultin a closure device that is responsive and able to reach and/or ligatetarget tissues with various shapes, orientations, and locations.

FIGS. 19A-19C depict a variation of the elongate body (600) depicted inFIGS. 6A-6G comprising two additional portions and transitionspositioned between a proximal end of the elongate body and the firsttransition (606), which may increase the flexibility of the middleand/or distal parts of the elongate body. FIG. 19A depicts a perspectiveview of the elongate body (1900), while FIGS. 19B and 19C depict a sideand bottom views, respectively. In this variation, the elongate body(1900) may comprise five portions and four transitions: a first portion(1904), a first transition (1903), a second portion (1905), a secondtransition (1907), a third portion (1909), a third transition (1906), afourth portion (1908), a fourth transition (1910), and a fifth portion(1912). In this variation, the first portion (1904) and third portion(1909) may comprise circular cross-sectional shapes, while the secondportion (1905), fourth portion (1908), and fifth portion (1912) maycomprise D-shaped cross-sectional shapes. For example, the first andthird portions (1904, 1909) may have a cross-section similar to or thesame as the cross-section of the first portion (604) in the embodimentshown in FIG. 6A, depicted in FIG. 6D. The second and fourth portions(1905, 1908) may have a cross-section similar to or the same as thecross-section of the second portion (608) in the embodiment shown inFIG. 6A, depicted in FIG. 6E. The fifth portion (1912) may have across-section similar to or the same as the cross-section of the thirdportion (612) in the embodiment shown in FIG. 6A, depicted in FIG. 6F.It should be appreciated that the diameters and/or heights (605, 609,611) may vary between the embodiment shown in FIG. 6A and that shown inFIG. 19A.

In this variation, the first, second, third, and fourth transitions(1903, 1907, 1906, 1910) may be similar to the first and secondtransitions (606, 610) in the embodiment depicted in FIG. 6A. Forexample, the first, second, third, and fourth transitions (1903, 1907,1909, 1910) may also comprise an angled, ramped, tapered, and/or beveledsurface (1914, 1916, 1918, 1920). In this variation, the firsttransition (1903) may be positioned between and connect the firstportion (1904) and the second portion (1905), the second transition(1907) may be positioned between and connect the second portion (1905)and the third portion (1909), the third transition (1906) may bepositioned between and connect the third portion (1909) and the fourthportion (1908), and the fourth transition (1910) may be positionedbetween and connect the fourth portion (1908) and the fifth portion(1912). As described above with respect to the embodiment depicted inFIGS. 6A-6G, in some variations, the fifth portion (1912) may have a tip(e.g., tip 603) covering it.

FIG. 20 depicts another variation of the elongate bodies (600, 1900)depicted in FIGS. 6A-6G and 19A-19C. In this variation, the elongatebody (2000) may also comprise five portions and four transitions: afirst portion (2004), a first transition (2003), a second portion(2005), a second transition (2007), a third portion (2009), a thirdtransition (2006), a fourth portion (2008), a fourth transition (2010),and a fifth portion (2012), but the fourth portion (2008) may bescalloped, which may increase flexibility in a localized region (e.g.,the fourth portion (2008)) of the elongate body (2000). For example, thefourth portion (2008) may comprise alternating regions: a first region(2014) with D-shaped cross-section similar to or the same as thatdepicted in FIG. 6E and a second region (2016) with D-shapedcross-section similar to or the same as that depicted in FIG. 6F. Thus,the first region (2014) may comprise a lumen (2018), while the secondregion (2016) may not. It should be appreciated that in some variations,the height of the elongate body (2000) in the second region (2016) maybe the same as the height of the elongate body (2000) in the fifthportion (2012), while in other variations the height of the elongatebody (2000) in the second region (2016) may be greater than or less thanthe height of the elongate body (2000) in the fifth portion (2012). Insome instances, and as depicted in FIG. 20, the second region (2016) maycomprise a concave lower surface (2020) instead of a flat lower surface.Additionally, in some variations, the second portion (2005) may also bescalloped and the fourth portion (2008) may or may not be scalloped(i.e., the fourth portion (2008) may have a similar construction as thefourth portion (1908) shown in FIGS. 19A-19C)).

While the first and second regions (2014, 2016) are shown having thesame or similar lengths, this need not be the case. In some instances,the first regions (2014) may be longer than the second regions (2016),while in other variations the second regions (2016) may be longer thanfirst regions (2014). In some variations, the lengths of the first andsecond regions (2014, 2016) may vary between occurrences of the regions.In addition, the elongate body (2000) may comprise any suitable numberof first and second regions (e.g., 3, 4, 5, 6, 7, 8, 9, 10, or more),and need not contain the same number of each region.

As described above, the closure devices described here may be advancedto the LAA along a guide wire housed in a lumen (e.g., the third lumen)of the elongate body of the closure device. In some variations and aslater described, a guide device may also be used to assist in advancingand retracting the guide wire and the closure device. In thesevariations, the configuration of the elongate body of the closure devicemay assist in managing the guide wire during retraction through theguide device and may therefore reduce the likelihood of the guide wirewrapping around the closure device or otherwise interfering withretraction of the closure device.

In use, after suture loop deployment, both the closure device and theguide wire may be retracted through the guide device. However, in somevariations, the diameter of the guide device may be too small toaccommodate passage of both the closure device and the guide wireside-by-side, especially in variations in which the guide wire comprisesan alignment member with a larger diameter than the guide wire, forexample, a magnet, at its distal tip. Thus, in order to remove the guidewire and the closure device through the guide device and prevent theguide wire from wrapping around or otherwise interfering with theremoval of the closure device, the guide wire may be centered orotherwise positioned along and against an underside of the elongate bodywhile the elongate body is retracted, after which the guide wire mayalso be retracted.

Accordingly, to assist in positioning the guide wire and closure devicefor retraction, in some variations, the guide wire (including thealignment element) may be advanced through the snare loop and distal tothe tip of the closure device. The guide wire may then be retracteduntil the alignment element is held against or is flush with theelongate body (e.g., at the first transition). Because the alignmentelement may have a larger diameter than the lumen through which theguide wire is slideably disposed (e.g., the third lumen), a portion ofthe elongate body may prevent the guide wire from being fully retractedinto the elongate body. For example, the guide wire may be retracteduntil the alignment element reaches an opening of the lumen, and uponcontinuous application of force to the proximal end of the guide wire,the alignment element may be held within or adjacent to the opening.This may center the alignment element next to and along the underside ofthe elongate body. The closure device may then be retracted into theguide device with the alignment element held centered against theunderside of the elongate body until the alignment element is disposedwithin the snare loop, at which point the loop and then the alignmentelement may be retracted into the guide device.

In variations of the elongate bodies described here comprisingadditional portions that may increase the bending flexibility of themiddle and/or distal sections of the elongate body, it may be desirableto maintain a portion of the elongate body for use in centering theguide wire so that the retraction method described above may beutilized. For example, referring to the elongate body shown in FIGS.19A-19C, the fourth and second portions (1908, 1905) may comprise athird lumen (1920) in the form of a groove, while the third portion(1909) may comprise a full third lumen (1920). Thus, when the elongatebody (1900) is used with a guide wire comprising an alignment elementcoupled to its distal end, the guide wire may be retracted until thealignment element reaches the distal opening (1922) of the third lumen(1920), at which point the diameter of the alignment element may preventfurther retraction of the guide wire. Thus the bottom surface of thethird transition (1906) and the third portion (1909) may act as analignment tool during retraction of the guide wire and closure device.Accordingly, although removing the third portion (1909) and second andthird transitions (1907, 1906) may result in a more flexible elongatebody, and thus may be desirable in some instances, doing so may make itmore difficult to retract the elongate body and closure device. Thus, insome variations, it may be desirable to include the third portion (1909)and second and third transitions (1907, 1906) at least because they mayassist in guide wire management during retraction.

Referring back to FIG. 6A, the collar (602) may connect the elongatebody (600) to the handle (not shown). The collar (602) may be integrallyformed with the elongate body (600), or it may be a separate componentand may be attached to the elongate body (600) as depicted in FIG. 6A.As shown in FIG. 6A, the collar (602) may comprise a lumen therethroughthrough which the proximal end of the elongate body (600) may beinserted. The collar (602) may be attached to the elongate body (600)and the handle using any suitable means (e.g., adhesive, bonding, andthe like). In some embodiments, the collar (602) may be integrallyformed with the handle. In some variations, the collar (602) may preventthe elongate body (600) from rotating with respect to the handle, whilein other variations, the collar (602) may be attached to a toggle thatenables a user to rotate the collar such that the entire elongate bodymay rotate with respect to the handle, as described in more detail inthe U.S. Provisional Patent Application titled “Tissue Ligation Devicesand Methods Therefor”, and filed on Mar. 24, 2015.

In some variations, the elongate body (600) may also comprise markers(614) that may provide an indication of the location of the device inthe body or in relation to another device or element (e.g., a guidedevice). These markers (614) may be especially useful when using aminimally invasive approach. The markers may comprise any suitableimaging element, for example, a visual, radiopaque, or echogenic marker,and may be attached to the elongate body in any suitable manner (e.g.,printed on, adhesive, rings, and the like). The elongate body (600) maycomprise any suitable number of markers (614), for example, one, two,three, four, or five, and the markers may be located at any suitablelocation along the length of the elongate body (600).

In some embodiments, the markers (614) may be placed at specificlocations along the elongate body (600) to provide information to a userabout the interaction of the elongate body with a guide device. Forexample, the markers (614) may be placed such that a marker may becomeapparent when the distal tip or a particular portion (e.g., the firstportion, the second portion, the third portion, a transition, and thelike) of the elongate body enters or exits a guide device. In someembodiments, the markers may be placed equidistant along the elongatebody instead, which may provide a clear indication of how much of theelongate body is within a patient's body. In some variations, theplacement of the markers (614) along the elongate body may allow a userto decrease the amount of time an imaging mechanism (e.g., radiation) isneeded because the user may better understand the location of the devicein a patient's body without imaging throughout an entire procedure.

Stiffened Portion

In some embodiments, the elongate body may comprise one or morestiffened portions that may prevent sections of the elongate body frombending or twisting undesirably during a procedure. In use, the elongatebody may be forced into fairly significant curvatures due to patientanatomy, and it may be useful for the device to maintain the originalorientation of the snare and suture loop during deployment.Additionally, a user may want to rotate the elongate body using thehandle of the device (which may be outside a patient's body), and it maybe desirable for the rotation of the handle to cause the distal tip ofthe elongate body to rotate the same or a similar amount as the handle(i.e., for there to be one-to-one rotation between the handle and thedistal tip of the elongate body). This may provide a user with bettercontrol over the device and may make the device easier to maneuver.However, because the device may be advanced through a patient's body, itmay also be desirable for the device to maintain some flexibility toprevent tissue damage and to allow the device to reach the LAA when thepath is fairly tortuous. Thus, it may be desirable for the elongate bodyto be configured to resist twisting, while still being able to bend.

In some embodiments, the stiffened portion of the elongate body may beformed such that it is stiffer than the other portions of the elongatebody. In some instances, the stiffened portion of the elongate body maycomprise a braided catheter, and the flexible portion or portions maycomprise a catheter made of the same or a similar material as the coreof the braided catheter (i.e., the core material without the braidedmaterial). For example, the braided catheter may comprise a polyetherblock amide core with a stainless steel braid, and the flexibleportion(s) may comprise polyether block amide (or a material withsimilar flexibility) without the stainless steel braid. In somevariations, the stiffened portion may comprise a different material thanthe flexible portion. For example, the stiffened portion may comprise anylon, and/or a hard polymer, and the flexible portion may comprise asoft polymer. In some variations, the stiffened and flexible portionsmay comprise materials with variable durometers such that the materialof the stiffened portion has a higher durometer than the material of theflexible portion. In some embodiments, the thickness of the elongatebody may vary such that the stiffened portion has a greater thicknessthan the flexible portion.

In some embodiments, the stiffened portion of the elongate body maycomprise a catheter and one or more stiffening elements. As their namesuggests, the stiffening elements may be designed to increase thestiffness of the elongate body relative to other sections of theelongate body that do not have stiffening elements. The portions of theelongate body that may be more flexible than the stiffened portion ofthe elongate body may be referred to as flexible portions, however, itshould be appreciated that the entire elongate body may be flexible. Theelongate body may comprise any suitable stiffening element(s). Forexample, in some embodiments, the stiffening element may comprise abraided sheath that may be adhered, or otherwise attached, to thecatheter. For example, the construction of the braided sheath may besimilar to that of the braid in the braided catheter, but the sheath maybe fabricated separately from the catheter body and may be bonded to anexternal surface of the catheter body. In some variations, thestiffening element may be embedded within a wall of the elongate body.For example, the stiffening element may comprise a wire or other stiffmaterial in a wall of the catheter. In other embodiments, the stiffeningelement may be housed within, or otherwise coupled to, a lumen of theelongate body. For example, in some variations, the stiffening elementmay comprise a wire or a hypotube (e.g., a stainless steel tube) coupledto a lumen of the elongate body. In other variations, the stiffeningelement may comprise a polymer tube that is more resistant to bendingthan the catheter, and the polymer tube may be disposed within, orcoupled to, a lumen of the elongate body. The stiffening element may becoupled to the lumen of the catheter in any suitable manner, including,but not limited to, bonding, adhesive, shrink-fit, reflowing, coating,and the like.

FIG. 7 depicts an elongate body (700) having a proximal end (701) and adistal end (703), and comprising a stiffened proximal portion (702), aflexible middle portion (704), a transition (706), a flexible distalportion (708), and markers (710). The stiffened proximal portion (702)may be located at the proximal-most end of the elongate body and may becoupled to a collar, which may in turn be coupled to a handle (asdescribed above with respect to FIG. 6A). The flexible middle portion(704) may be located between the proximal stiffened portion (702) andthe transition (706), and the transition (706) may be located betweenthe flexible middle portion (704) and the flexible distal portion (708).The markers (710) may assist a user with visualization of the deviceduring a procedure, as is described above with respect to the markers(614) in FIG. 6A. While FIG. 7 includes one stiffened portion, twoflexible portions, and one transition, the elongate body (700) maycomprise any suitable number of stiffened portions (e.g., one, two,three, or four), transitions (e.g., one, two, three, four, five, ormore), and flexible portions (e.g., one, two, three, four, five, six, ormore). For example, as will be described in more detail below, in somevariations, the elongate body (700) may comprise two flexible middleportions and two transitions. In other variations, the elongate body(700) may comprise four flexible middle portions and four transitions.Additionally, in some variations, the elongate body (700) may comprise astiffened portion between flexible portions, or vice versa.

As mentioned above, in some variations, the closure device may furthercomprise a tip (e.g., tip (603) shown in FIG. 6G) coupled to, disposedover, and/or fixedly attached to (e.g., using adhesive or the like) theflexible distal portion of the elongate body. As also described above,in some variations, the tip may be hard or rigid and may thereforeprevent the flexible distal portion from bending. In these variations,the flexible distal portion may no longer be flexible. In othervariations comprising a tip, the tip may also be flexible such that theflexible distal portion remains flexible.

In some variations, the elongate body (700) may further comprise ajacket (712) over the entire external surface of the elongate body orjust a portion of it. The jacket may be used to smooth the externalsurface of the elongate body and/or to increase the thickness of theelongate body, which may in turn modify its bending and/or torsionalresistance. In some embodiments, the elongate body may comprise a jacket(712) over the stiffened proximal portion (702) and the flexible middleportion (704), but the jacket (712) may not extend over the transition(706) and the flexible distal portion (708). In some variations, thejacket (712) may extend over the stiffened proximal portion (702), theflexible middle portion (704), and the transition (706), but may notinclude the flexible distal portion (708). In still other embodiments,the jacket (712) may extend the entire length of the elongate body(700). The jacket (712) may be coupled to an external surface of theelongate body (700) by lamination, adhesion, bonding, or any othersuitable technique, and may comprise any suitable polymer (e.g.,polyether block amide).

As mentioned above, in some embodiments, the stiffened proximal portion(702) may comprise a braided catheter. The braid of the braided cathetermay be formed from any suitable wire (i.e., 0.002 inch (0.0508 mm)thickness circular wire, 0.001 inch×0.007 inch (0.0254 mm×0.1778 mm)rectangular wire, a combination of the two, circular or rectangular wirewith different dimensions, and the like). The wire may be any suitablematerial, for example, stainless steel, and may be annealed if desired.The braided catheter may be formed using a reflow process such that thebraid becomes integral with the catheter and is embedded in the wall ofthe catheter, as opposed to attached to an external surface of thecatheter using, for example, adhesive (which is also contemplated and isdescribed in more detail below). Using an elongate body with the braidembedded within a wall of the catheter (braided catheter) may affect theresponsiveness of the elongate body to torque applied to the handle ofthe device. For example, the integration of the braid into thecatheter's core material may modify the distribution of force within andalong the elongate body. In some instances, the material closest to theexternal surface of the elongate body may have a larger impact on thetorsional response of the elongate body. In these instances, varying thelocation of the braid within the wall of the catheter may affect itstorsional response, which may in turn impact a user's ability to steerand control the distal tip of the elongate body.

In some instances, the cross-sectional shape and diameter and/or heightof the elongate body may vary throughout the elongate body, as describedin detail above, and the elongate body may also comprise a stiffenedproximal portion (702), a flexible middle portion (704), and a flexibledistal portion (708). In some instances, the stiffened and flexibleportions of the elongate body may correspond to (i.e., have the samelocation, length, cross-sectional shape, and/or lumen configuration) thefirst, second, and third portions (604, 608, 612) of the elongate body(600) illustrated in FIG. 6A, whereas in other variations, the first,second, and third portions (604, 608, 612) may overlap or otherwiseinclude more than one of the stiffened proximal, flexible middle, andflexible distal portions. For example, in the embodiment depicted inFIG. 7, the stiffened proximal portion (702) may be located within thefirst portion (604), the flexible middle portion (704) may be located inboth the first portion (604) and the second portion (608), and theflexible distal portion may be located in the third portion (612). Asmentioned above, in some instances, a rigid tip may be coupled to theflexible distal portion, which may result in a rigid distal portion.

The stiffened and flexible portions may have any suitablecross-sectional shape (e.g., circular, oval, D-shaped, and the like) anddiameter or height. In some embodiments, the elongate body (700) mayhave a circular cross-sectional shape along its entire length. In otherembodiments, the stiffened proximal portion (702) may have a circularcross-sectional shape with a first diameter, the flexible middle portion(704) may have a circular cross-sectional shape with a second diameter,and the flexible distal portion (708) may have a D-shapedcross-sectional shape with a height. In these embodiments, the firstdiameter may be greater than the second diameter, which may be greaterthan the height.

For example, the stiffened proximal portion (702) may have a diameterbetween about 0.160 inches (4.064 mm) and about 0.169 inches (4.293 mm).In some variations, the stiffened proximal portion (702) may have adiameter of about 0.163 inches (4.140 mm). The flexible middle portion(704) may have a diameter between about 0.156 inches (3.962 mm) andabout 0.162 inches (4.115 mm). In some embodiments, the flexible middleportion (704) may have a diameter of about 0.160 inches (4.064 mm). Theflexible distal portion (708) may have diameter of about 0.144 inches(3.658 mm) to about 0.150 inches (3.81 mm). In some embodiments, theflexible distal portion (708) may have a diameter of about 0.148 inches(3.760 mm). In some variations, the flexible distal portion (708) mayhave a height of about 0.094 inches (2.388 mm) to about 0.098 inches(2.489 mm). In some embodiments, the flexible distal portion (708) mayhave a height of about 0.096 inches (2.438 mm). In some embodiments, thediameter of the stiffened proximal portion may be less than or equal toabout 1.00, 1.02, 1.04, 1.06, 1.08, or 1.10 times the diameter of theflexible middle portion.

In some variations, the elongate body (700) may comprise multipleflexible middle portions and multiple transitions. For example, in oneembodiment, the elongate body (700) may comprise a stiffened proximalportion (702), first and second flexible middle portions, first andsecond transitions, and a flexible distal portion (708). The firstflexible middle portion may be just distal of the stiffened proximalportion (702) and just proximal of the first transition, and the secondflexible middle portion may be between the first transition and thesecond transition (e.g., transition (706)). With reference to FIG. 6A,in these embodiments, the stiffened proximal portion (702) and the firstflexible middle portion may be located in the first portion (604), thesecond flexible middle portion may correspond to the second portion(608), and the flexible distal portion (708) may correspond to the thirdportion (612). The first and second transitions may correspond to thefirst and second transitions (606, 610).

In this variation, the stiffened proximal portion (702) may have acircular cross-sectional shape with a first diameter, the first flexiblemiddle portion may have a circular cross-sectional shape with a seconddiameter, the second flexible middle portion may have a D-shapedcross-sectional shape with a first height, and the flexible distalportion (706) may have a D-shaped cross-sectional shape with a secondheight. In these variations, the first diameter may be greater than thesecond diameter, which may be greater than the first height, which maybe greater than the second height; however, this need not be the case.

For example, the stiffened proximal portion and flexible distal portionmay have the diameters/heights described above and the first flexiblemiddle portion may have a diameter of about 0.156 inches (3.962 mm) toabout 0.162 inches (4.115 mm), and the second flexible middle portionmay have a height of about 0.116 inches (2.946 mm) to about 0.122 inches(3.099 mm). In some variations, the first flexible middle portion mayhave a minimum diameter of about 0.158 inches (4.013 mm), and the secondflexible middle portion may have a height of about 0.120 inches (3.048mm).

In another variation, the elongate body (700) may comprise a stiffenedproximal portion (702), a first flexible middle portion, a firsttransition, a second flexible middle portion, a second transition, athird flexible middle portion, a third transition, a fourth flexiblemiddle portion, a fourth transition (706), and a flexible distal portion(708). In this embodiment, the flexible middle portion (704) may includethe first, second, third and fourth flexible middle portions and thefirst, second, and third transitions (not shown). The stiffened andflexible portions and the transitions may be located within orcorrespond to the portions and transitions of the elongate body (1900)depicted in FIGS. 19A-19C. For example, the stiffened proximal portion(702) and first flexible middle portion may be located within the firstportion (1904). The second, third, and fourth flexible middle portionsmay correspond to the second, third, and fourth portions (1905, 1909,1908) respectively, and the flexible distal portion (708) may correspondto the fifth portion (1912). Additionally, the first, second, third, andfourth transitions may correspond to the first, second, third, andfourth transition (1903, 1907, 1906, 1910), respectively.

In this variation, the stiffened proximal portion (702) may have acircular cross-sectional shape with a first diameter, the first flexiblemiddle portion may have a circular cross-sectional shape with a seconddiameter, the second flexible middle portion may have a D-shapedcross-sectional shape with a first height, the third flexible middleportion may have a circular cross-sectional shape with a third diameter,the fourth flexible middle portion may have a D-shaped cross-sectionalshape with a second height, and the flexible distal portion (706) mayhave a D-shaped cross-sectional shape with a third height. In thesevariations, the first diameter may be greater than the second diameter,which may be the same as the third diameter. The second and thirddiameters may be greater than the first height, which may be the same asthe second height. The first and second heights may be greater than thethird height; however, this need not be the case.

For example, the stiffened proximal portion and flexible distal portionmay have the diameters/heights described above, the first and thirdflexible middle portions may have a diameter of about 0.145 inches(3.683 mm) to about 0.151 inches (3.835 mm) and the second and fourthflexible middle portions may have a height of about 0.096 inches (2.438mm) to about 0.120 inches (3.048 mm). In some variations, the first andthird flexible middle portions may have a diameter of about 0.148 inches(3.759 mm) and the second and fourth flexible middle portions may have aheight of about 0.108 inches (2.743 mm). While the first and thirdflexible middle portions and second and fourth flexible middle portionsare described above has having the same diameters and heightsrespectively, this need not be the case. In some variations, thediameter of the first flexible middle portion may be greater than thediameter of the third flexible middle portion, or vice versa.Additionally, in some instances, the height of the second flexiblemiddle portion may be greater than the height of the fourth flexiblemiddle portion, and vice versa.

As mentioned above with respect to FIGS. 19A-19C, it may be desirable toutilize an elongate body comprising additional flexible middle portions,especially in combination with a stiffened proximal portion, to increasethe bending flexibility of the middle and/or distal parts of theelongate body. This increased bending flexibility may assist in accessto and ligation of hard to reach tissue. Additionally, as also describedabove, using a catheter with a curved distal segment may also assist inaccessing and ligating tissue, and the cross-sectional shape,cross-sectional diameter/height, number of flexible portions and/ornumber and type of proximal stiffening elements may determine what angle(1812) and radius (1810) may be most desirable for a particularprocedure. For example, in this variation and/or the variation describedabove with respect to FIG. 7 comprising multiple flexible middleportions, and when the target tissue is the LAA, it may be desirable touse an elongate body with a curved distal segment having an angle ofabout 86 to about 88 degrees and a radius of about 3.10 inches (7.87 cm)to about 3.40 inches (8.64 cm). In some instances, it may be desirableto use an elongate body with a curved distal segment having an angle ofabout 87 degrees and a radius of about 3.30 inches (8.38 cm).

The foregoing diameters and heights are exemplary and the stiffenedproximal portion (702), flexible middle portion (704) or portions, andflexible distal portion (708) may have any suitable diameters orheights.

It should be appreciated that the diameters and/or heights of thestiffened portion(s) and flexible portion(s) of the elongate body mayaffect the torqueability of the elongate body and its responsiveness. Insome instances, the stiffened proximal portion may transmit the torqueapplied to the handle of the elongate body directly to the flexibleportion, but the flexible portion may not transmit all of the torque atits proximal end to its distal end. Put another way, in some instances,the elongate body will twist at a point or in regions along its lengthwhen the handle is rotated, which may prevent the distal end of theelongate body from rotating the same or a similar amount as the handle.In these instances, the elongate body has a low torsional response.Modifying the diameters and/or heights, lengths, and/or stiffness of thevarious portions of the elongate body may vary the amount of angulartwist between the handle and the distal end of the elongate body and mayincrease the torsional response of the elongate body. In particular,varying the diameter of the flexible portion of the elongate body mayhave a greater effect on torsional response than varying the diameter ofthe stiffened portion. Because it may be desirable for the rotation ofthe elongate body to mirror the rotation of the handle to the extentpossible, meaning that the rotation angle (i.e., 5 degrees, 10 degrees,15 degrees, 30 degrees, etc.) of the distal tip of the elongate bodymatches the rotation angle of the handle (i.e., how much a user rotatesthe handle), it may be desirable to vary the diameter and/or height ofthe flexible portion with respect to the stiffened portion. For example,in some embodiments, the elongate body may be configured such thatrotating the handle 180 degrees causes the distal tip of the elongatebody (700) to rotate at least 120 degrees, 140 degrees, 160 degrees, 175degrees, and/or 180 degrees. In embodiments in which rotating the handle180 degrees causes the distal tip of the elongate body (700) to rotate180 degrees, the device has 1:1 rotation.

As mentioned above, the elongate body may comprise one or moretransitions connecting the portions of the elongate body comprisingdifferent diameters and/or different cross-sectional shapes. Thetransitions may provide smooth conversions between the differentportions of the elongate body, which may aid in maneuverability. Forexample, using transitions may remove abrupt diameter changes that maycause the elongate body to kink. In some variations, an abrupt change indiameter between different portions of the elongate body may act as astress-concentrator, which may make it more likely for the elongate bodyto kink or buckle at the transition when the elongate body is subjectedto external forces. In these variations, it may be desirable to havetransitions of sufficient lengths to decrease the stress concentrationat these points or regions and thus decrease the likelihood that theelongate body will kink or buckle.

Turning to FIGS. 8A-8C, shown there are perspective views of variationsof a transition (806A, 806B, 806C) positioned between a middle flexibleportion (804A, 804B, 804C) and a flexible distal portion (808A, 808B,808C) of an elongate body (800A, 800B, 800C). The transition (806A,806B, 806C) may have a diameter and/or height that matches the diameterand/or height of the flexible middle portion (804A, 804B, 804C) at thetransition's (806A, 806B, 806D) proximal end, and a diameter and/orheight that matches the diameter and/or height of the flexible distalportion (808A, 808B, 808C) at its distal end. For example, inembodiments in which the flexible middle portion (804A, 804B, 804C) hasa diameter of about 0.160 inches (4.064 mm) and the flexible distalportion (808A, 808B, 808C) has a diameter of about 0.148 inches (3.759mm), the transition (806A, 806B, 806C) may have a diameter of about0.160 inches (4.064 mm) at its proximal end and a diameter of about0.148 inches (3.759 mm) at its distal end. In embodiments comprising afirst flexible middle portion and a second flexible middle portion, atransition may be positioned between the second flexible middle portionand the flexible distal portion such that the proximal end of thetransition has a diameter and/or height equal to the diameter and/orheight of the second flexible middle portion, and the distal end of thetransition has a diameter and/or height equal to the diameter and/orheight of the flexible distal portion. In embodiments comprisingmultiple flexible middle portions, transitions may be positioned betweenthe flexible middle portions having diameters and/or heights that matchthe diameters and/or heights of the portions the transitions connect, asdescribed above. In some embodiments, the diameter and/or height of thetransition may decrease symmetrically, as depicted in FIGS. 8A and 8C,while in other embodiments, the diameter and/or height of the transitionmay decrease asymmetrically, as depicted in FIG. 8B. Moreover, in somevariations, the transition may comprise one or more angled surfaces(810A, 810B) such that the transition is tapered and its diametergradually changes, as shown in FIGS. 8A and 8B. In other variations, thetransition may comprise a vertical or substantially vertical surface(812) such that a shoulder or ledge is formed and its diameter abruptlychanges, as shown in FIG. 8C. In yet other variations, the transitionmay comprise a combination of angled and vertical surfaces.

The stiffened proximal portion (702), flexible middle portion (704),transition (706), and flexible distal portion (708) may also have anysuitable lengths. For example, the stiffened proximal portion (702) mayhave a length of about 12.00 inches (30.48 cm) to about 14.00 inches(35.56 cm). In some variations, the stiffened proximal portion (702) mayhave a length of about 13.00 inches (33.02 cm). The flexible middleportion (704) may have a length of about 3.50 inches (8.89 cm) to about5.00 inches (12.70 cm). In some variations, the flexible middle portion(704) may have a length of about 4.20 inches (10.67 cm). The flexibledistal portion (708) may have a length of about 0.20 inches (5.08 mm) toabout 0.40 inches (10.16 mm). In some variations, the flexible distalportion (708) may have a length of about 0.25 inches (6.35 mm). In someembodiments, the length of the stiffened proximal portion (702) may beat least about 2.25, 2.50, 2.75, 3.00, 3.25, or 3.50 times greater thanthe length of the flexible middle portion.

In embodiments comprising a first flexible middle portion and a secondflexible middle portion, the first flexible middle portion may have alength of about 1.50 inches (3.81 cm) to about 2.50 inches (6.35 cm),and the second flexible middle portion may have a length of about 2.00inches (5.08 cm) to about 3.00 inches (7.62 cm). In some variations, thefirst flexible middle portion may have a length of about 1.90 inches(4.83 cm), and the second flexible middle portion may have a length ofabout 2.30 inches (5.84 cm). In some embodiments, the transition mayhave a length of about 0.070 inches (1.78 mm) to about 0.085 inches(2.16 mm). In some variations, the transition may have a length of atleast 0.075 inches (1.91 mm).

In embodiments comprising first, second, third and fourth flexiblemiddle portions, the first flexible middle portion may have a length ofabout 0.175 inches (4.45 mm) to about 0.220 inches (5.59 mm), the secondflexible middle portion may have a length of about 1.20 inches (3.05 cm)to about 1.26 inches (3.20 cm), the third flexible middle portion mayhave a length of about 0.08 inches (0.20 cm) to about 0.16 inches (0.41cm), and the fourth flexible middle portion may have a length of about2.25 inches (5.72 cm) to about 3.25 inches (8.23 cm). In somevariations, the first flexible middle portion may have a length of about0.198 inches (5.03 mm), the second flexible middle portion may have alength of about 1.23 inches (3.12 cm), the third flexible middle portionmay have a length of about 0.12 inches (0.30 cm), and the fourthflexible middle portion may have a length of about 2.75 inches (6.99cm). In some embodiments, the first, second, and third transitions mayhave a length of about 0.067 inches (1.70 mm) to about 0.167 inches(4.24 mm), or more particularly, from about 0.097 inches (2.46 mm) toabout 0.137 inches (3.48 mm), and the fourth transition may have alength of about 0.060 inches (1.52 mm) to about 0.080 inches (2.03 mm).In some variations, the first, second, and third transitions may have alength of about 0.117 inches (2.97 mm) and the fourth transition mayhave a length of about 0.067 inches (1.70 mm). Although the first,second, and third transitions may have the same length, they need not.

It should be appreciated that the elongate body (700) described in FIG.7 may comprise any suitable number and configuration of lumens. Forexample, the elongate body may comprise one or more lumens in any of theconfigurations described with respect to FIGS. 5A, 5B, and 6B.

In some variations, the elongate body may comprise more than onemechanism or element that may increase its stiffness. For example, theelongate body may comprise a stiffened proximal portion as describedabove and may additionally further comprise a second stiffeningmechanism. FIG. 9 depicts an example of an embodiment comprising astiffened proximal portion and a second stiffening element. FIG. 9 showsan exploded view of an elongate body (900) comprising a collar (902) atits proximal end, a catheter (904), a second stiffening element (906),and markers (908). The elongate body (900) may comprise a stiffenedproximal portion, for example, a braided catheter, and any number offlexible portions and transitions. The elongate body (900) is depictedcomprising four lumens, but may comprise any suitable number of lumens,as described above in detail. In this embodiment, the second stiffeningelement (906) may be fixedly disposed within a lumen of the elongatebody (900) and may be any element configured to increase the rigidity ofthe catheter (904) compared to portions of the catheter without thesecond stiffening element (906). For example, the second stiffeningelement (906) may comprise a polymer tube that is more resistant tobending than the catheter (904) (stiffened or flexible portions), ahypotube (e.g., a stainless steel tube), or any other element configuredto increase the stiffness of the catheter (904). The elongate body (900)may optionally comprise an opening (e.g., a slot, groove, or hole) (910)at its proximal end, which may be used to contain an adhesive and/orepoxy to couple the second stiffening element (906) to the catheter(904).

In some variations, the second stiffening element (906) may comprise apattern (912). The pattern (912) may comprise a series of lines orshapes cut in the second stiffening element (906) that may make thesecond stiffening element (906) more flexible. It may be desirable touse a stiffening element comprising a pattern because doing so may allowmore control over the increase in the stiffness of the elongate body dueto presence of the second stiffening element (906). Referring now toFIGS. 10A and 10B, shown there are variations of a second stiffeningelement (1000A, 1000B) comprising a pattern (1002A, 1002B) cut in it.While depicted as a spiral cut pattern, any suitable cut pattern may beemployed (e.g., longitudinal or concentric grooves, slits, aperturepatterns, and the like.). The pattern may be cut using any suitablemeans, for example, a sharpened tool, an electric source (e.g., alaser), a thermal source, and the like. In some instances, the cutpattern may begin at the proximal end of the second stiffening element(1000A, 1000B) and may continue its entire length, whereas in othervariations, the cut pattern may begin at a location distal to theproximal end of the second stiffening element (1000A, 1000B) and maytravel any desired distance toward its distal end. Additionally, the cutpattern may optionally be discontinuous and include breaks (1006) in thecut pattern (i.e., portions of the pattern that would otherwise be cutbut are instead uncut), as depicted in FIG. 10B.

The pattern (1002A, 1002B) may vary along the length of the secondstiffening element (1000A, 1000B), for example, as depicted in FIG. 10A.In some embodiments, the angle (θ_(A), θ_(B)) and/or the pitch (1004A,1004B) of the cut pattern may vary. In some variations, the angle(θ_(A), θ_(B)) may decrease and the pitch (1004A, 1004B) may increasefrom the distal to the proximal end of the second stiffening element(1000A, 1000B). This may provide an increased resistance to bending ortwisting at the proximal end, compared to the distal end, of the secondstiffening element (1000A, 1000B). It may be useful to have a stifferproximal end of the elongate body as discussed above, while maintainingthe flexibility of at least part of the middle and distal portions ofthe elongate body to decrease the risk of puncturing or otherwisedamaging tissue, and to maintain the elongate body's ability to travelthrough a curved guide device and/or tortuous anatomy. In othervariations, only one of the angle (θ_(A), θ_(B)) and the pitch (1004A,1004B) may vary along the length of the second stiffening element(1000A, 1000B). In yet other variations, the angle (θ_(A), θ_(B)) andthe pitch (1004A, 1004B) may remain constant.

The second stiffening element (906) may be any suitable length. In someembodiments, the second stiffening element (906) may be the same or asimilar length as the stiffened proximal portion, whereas in otherembodiments, the second stiffening element may be shorter than or longerthan the stiffened proximal portion. As used herein, “similar lengths”refers to lengths that are within ±10% of each other. In somevariations, the second stiffening element (906) may have a length equalto the length of the entire elongate body.

Malleable Shaft

In some instances, it may be desirable to modify the shape and/orcurvature of the elongate body to assist in accessing difficult-to-reachanatomy during a procedure. For example, when the devices described hereare used during a surgical procedure, it may be desirable to modify thecurvature of the elongate body prior to advancing the device into thebody, and it may be useful for the elongate body to maintain thatpre-set curvature throughout the procedure, or at least until reachingthe tissue to be ligated. Specifically, it may be desirable to curve theelongate body to better access the left atrial appendage with theclosure element based on positioning at the operating table and apatient's particular unique anatomy.

To enable modification of the shape and/or curvature of the elongatebody prior to using the device and allow the device to retain that shapeand/or curvature during a procedure, in some embodiments, the elongatebody may comprise a malleable member. The malleable member may make theelongate body shapeable. In these embodiments, when a force is appliedto the elongate body to curve, bend, or otherwise place it in aparticular shaped configuration, the malleable member may maintain thatcurvature, bend, or shape after the force has been removed or released,thus causing the elongate body to also maintain that curvature, bend, orshape.

The malleable member may be attached to the elongate body in anysuitable fashion, including being disposed around the external surfaceof the elongate body, being disposed in or coupled to a lumen of theelongate body, and/or being embedded in a wall of the elongate body. Itshould be appreciated that the device may comprise any number of lumensand the lumens may have any suitable configuration, for example, any ofthe configurations described above with respect to FIGS. 5A, 5B and 6B.In embodiments comprising more than one lumen, the malleable member maybe placed in any suitable lumen, for example, the first lumen, thesecond lumen, the third lumen, or the fourth lumen. In some instances,the malleable member may comprise a proximal end and a distal end, andthe proximal end of the malleable member may be fixedly attached to aproximal end of the elongate body, and the distal end of the malleablemember may be fixedly attached to the distal end of the elongate body.In variations in which the malleable member may be disposed within alumen of the elongate body, for example, the third lumen, the proximalend of the malleable member may be fixedly attached to the proximal endof the third lumen, and the distal end of the malleable member may befixedly attached to the distal end of the third lumen. The malleablemember may be attached to the elongate body using any suitable means,for example, adhesive, bonding, and the like. In some embodiments, themalleable member may be disposed in a lumen of the elongate body, but itmay not be physically adhered to the lumen.

FIGS. 11A and 11B depict variations of a device (1100A, 1100B) forligating tissue comprising a handle (1102A, 1102B), an elongate body(1104A, 1104B), a snare loop assembly (1106A, 1106B), and a malleablemember (1108A, 1108B). FIG. 11C depicts a cross-sectional view of theelongate body (1104A) of the device (1100A) of FIG. 11A comprising afirst lumen (1112), a second lumen (1114), a third lumen (1116), and amalleable member (1108A). In these variations, the malleable member(1108A, 1108B) is depicted in the form of a shapeable jacket. Theshapeable jacket may surround the elongate body (1104A, 1104B) and maybe coupled to an external surface of the elongate body (1104A, 1104B);however, the shapeable jacket may be disposed within and/or coupled to alumen of the elongate body (1104, 1104B). The shapeable jacket may becoupled to the elongate body (1104A, 1104B) using any suitable means,including but not limited to, adhesive, epoxy and/or bonding, throughoutthe entire length of the shapeable jacket or on the proximal and/ordistal ends of the shapeable jacket. The shapeable jacket may be fixedlyattached to the elongate body (1104A, 1104B) such that the shapeablejacket cannot rotate or move longitudinally with respect to the elongatebody (1104A, 1104B); however, it need not be. Moreover, the shapeablejacket may be made of any suitable malleable material, for example,stainless steel, shapeable polymers, and the like. In some variations,the shapeable jacket may be annealed. As depicted in FIG. 11B, in somevariations, the malleable member (1108B) may comprise a cut pattern(1110B). The cut pattern (1110B) may vary along its length (e.g., inangle and pitch), as described above with respect to FIGS. 10A and 10B.In some variations, the thickness of the shapeable jacket may vary alongthe length of the shapeable jacket and therefore the length of theelongate body. For example, in some instances, the shapeable jacket maybe thicker at its proximal end and thinner at its distal end. Varyingthe thickness of the shapeable jacket may provide the elongate body withmore resistance to bending in locations where the shapeable jacket isthicker and less resistance to bending (i.e., it may be more flexibleand easier to manipulate) in locations where the shapeable jacket isthinner. This may assist with the pushability and maneuverability of theclosure device.

In some instances, the malleable member may comprise a shapeable wiredisposed within a lumen of the elongate body (1104A, 1104B). The wiremay be fixedly attached to the proximal and/or distal ends of theelongate body (1104A, 1104B), or the wire may be fixedly attached to theelongate body (1104A, 1104B) throughout its length. The wire may be madeof any suitable malleable material, and in some instances, may be astainless steel annealed wire. In some variations, the wire may beembedded within a wall of the elongate body (1104A, 1104B). In someembodiments, the device (1100A, 1100B) may comprise multiple malleablemembers. For example, the closure device may comprise both a shapeablejacket and a shapeable wire.

In some variations, the device may comprise a pull wire that may modifythe curvature or shape of the malleable member and thus the elongatebody. For example, in some embodiments, the closure device may comprisea pull wire and a shapeable jacket. The wire may be coupled to thedistal end of the elongate body (1104A, 1104B) and to an actuator (e.g.,a slider, knob, etc.) in the handle of the device. When the actuator isengaged, the pull wire may apply a force to the distal end of theelongate body to deflect it, curve the elongate body, and/or move itinto a preferred shape. The actuator may then be disengaged, and theshapeable jacket or other malleable member may retain the curvature orshape, which may cause the elongate body to remain curved or shaped. Thewire may have any suitable diameter and may be a round wire, a flatwire, or may comprise any suitable cross-sectional shape.

Visualization Tool

In some embodiments, the closure device may further comprise one or morevisualization tools configured to allow a user to view the distal end ofthe elongate body, the snare loop assembly, and/or the tissuesurrounding it during a procedure. The visualization tool may compriseany tool that may assist a user in viewing the end of the elongate body,the snare and/or snare loop assembly, and/or the surrounding tissueduring a procedure. For example, in some embodiments, the visualizationtool may comprise a scope (e.g., an endoscope), a light, a camera, orthe like. The visualization tool may be a separate tool that is usedwith the closure device, or it may be part of the closure device itself.In embodiments in which the visualization tool is part of the closuredevice, the device may comprise a power source (e.g., batteries) for thevisualization tool within its handle, or the visualization tool may beconnectable to an external power source. The wires and/or otherelectronic components necessary to power the visualization tool, orotherwise enable the tool to function, and/or store images from thevisualization tool, may be housed in any suitable location within thedevice. For example, the wires or other electronic components may behoused within a lumen of the elongate body or on or within the handle.In other variations, the electronic components may be external to thedevice and connected to the device at any suitable location. Thevisualization tool may be slideably disposed within any suitable lumenof the elongate body, or it may be fixedly attached to the lumen (e.g.,at its proximal and/or distal end, in the center of the lumen, along aportion of the lumen, and the like) such that it will not move during aprocedure. In some embodiments, the visualization tool may be coupled toan external surface of the elongate body, fixedly or releasably, usingany suitable means (e.g., adhesive, bonding, snap fit elements, and thelike).

FIG. 12 depicts a closure device (1200) comprising an elongate body(1202) having a first lumen (1204), a second lumen (1206), a third lumen(1208), a snare (1210), and a visualization tool (1212). While depictedwith only the snare (1210), in some embodiments, the closure device(1200) may comprise a snare loop assembly, as described in more detailabove. The elongate body may have any of the configurations previouslydescribed with respect to FIGS. 5A, 5B, 6A-6C, 7, 9, and 11A-11C (i.e.,it may have any lumen configuration, multiple portions comprisingdifferent cross-sectional shapes and/or diameters, and/or it may havestiffened and flexible portions). As depicted here, the elongate bodymay comprise a first portion (1214) with a circular cross-sectionalshape, a second portion (1216) with a D-shaped cross-sectional shape,and a third portion (1218) with a circular cross-sectional shape. Thefirst and second lumens (1204, 1206) may house any component of thedevice as previously described, for example, portions of the snareand/or suture, while the third lumen (1208) may house the visualizationtool (1212). In some of the previously described embodiments in whicheach of the lumens already comprises components of the device, anadditional lumen may be added for the visualization tool, or thevisualization tool may share a lumen with other components.

Turning back to FIG. 12, the lumen housing the visualization tool maycomprise multiple entrances and exits, which may enable the use of thevisualization tool in multiple locations along the elongate body. Forexample, here, a portion of the third lumen (1208) is cut-away in thesecond portion (1216) of the elongate body (1202), and thus the thirdlumen (1208) has an exit at the distal end of the first portion (1214)and at the distal tip of the device. The visualization tool (1212) maybe used at either and/or both exits, or at any location between them.For example, in some instances, it may be beneficial for thevisualization tool (1212) to exit the elongate body (1202) at the distalend of the first portion (1214) such that the visualization tool (1212)is proximally off-set from the distal tip of the elongate body (1202).In these instances, keeping the visualization tool (1212) at a locationproximal to the distal tip of the elongate body (1202) may assist a userin viewing the closure element (1210), and the tissue surrounding it,during a procedure. In some instances, advancing the visualization tool(1212) to the distal tip of the elongate body (1202) may make itdifficult to view the closure element (1210).

However, at times, it may be beneficial to advance the visualizationtool (1212) to the distal tip of the device. For example, advancing thevisualization tool (1212) to the distal tip of the elongate body (1202)may allow a user to view the tissue in front of the device and thereforemay assist a user in steering and/or guiding the device through thebody. In some instances, a user may employ the visualization tool (1212)in multiple locations during a procedure by sliding or otherwise moving(e.g., retracting and/or advancing) the visualization tool (1212). Forexample, a user may advance the visualization tool (1212) to the distaltip of the elongate body (1202) for use while the device is advancedthrough the body to the tissue to be ligated, and the user may thenretract the visualization tool (1212) through a lumen of the elongatebody (1202) to a location proximal of the distal tip (e.g., to anylocation in the second portion (2016) of the elongate body), for usewhile the tissue is ligated.

FIG. 13A shows another embodiment of a closure device (1300) comprisingan elongate body (1302) having a first lumen (1304), a second lumen(1306), a third lumen (1308), a snare (1310), and a visualization tool(1312). While depicted with only the snare (1310), in some embodiments,the closure device (1300) may comprise a snare loop assembly, asdescribed in more detail above. FIG. 13B depicts a cross-sectional viewof the elongate body (1302) of the closure device (1300) of FIG. 13Aalong line BB, but it should be appreciated that the elongate body neednot have the depicted configuration and may instead have any of theconfigurations previously described with respect to FIGS. 5A-5B, 6A-6F,7, 9, and 11A-11C (i.e., it may have any lumen configuration, multipleportions comprising different cross-sectional shapes and/or diameters,and/or it may have stiffened and flexible portions). Here, the elongatebody (1302) may comprise a first portion (1314) with a circularcross-sectional shape, a second portion (1316) with a D-shapedcross-sectional shape distal to the first portion (1314) as depicted inFIG. 13B, and may have a tip (1318) on its distal end. The first,second, and third lumens (1304, 1306, 1308) may house any of thecomponents as previously described, including a visualization tool asdescribed with respect to FIG. 12 above. Additionally, the closuredevice (1300) shown here further comprises a jacket (1320), which mayact as a stiffening element or a malleable member, as described in moredetail above.

The closure device (1300) may comprise a visualization tool (1312) inthe form of a camera mounted on an external surface of the secondportion (1316) of the elongate body (1302), for example on the undersideof the device, as depicted in FIG. 13A. The visualization tool (1312)here may assist a user in viewing the tissue surrounding the deviceduring a procedure and may allow a user to capture still and movingimages while a procedure is performed. The captured images may beanalyzed during and/or after the procedure is completed. It should beappreciated that the visualization tool (1312) may be mounted on anysuitable external surface of the elongate body (1302) and need not be onthe underside of the device in the second portion (1316), as depicted.It should also be appreciated that mounting a visualization tool (1312)on an external surface of the elongate body (1302) may include mountingthe visualization tool (1312) within a wall of the elongate body (1302)such that the visualization tool (1312) lays flush with the externalsurface of the elongate body (1302).

Moreover, in some variations, the visualization tool (1312) may becoupled to the tip (1318), which may assist a user in viewing the tissuein front of the device (1300), as described above. In some embodiments,the closure device (1300) may comprise multiple visualization tools(1312) (e.g., two, three, four, five, and the like). For example, theclosure device (1300) may comprise multiple cameras, and/or the closuredevice (1300) may comprise a light disposed in a lumen of the elongatebody and one or more cameras mounted on an external surface of theelongate body (1302).

Handle and Tensioning Mechanism

As described above, the closure devices described here may comprise ahandle or other control mechanism. The handle may have any suitableshape or configuration, for example, any of those described in U.S.patent application Ser. No. 12/752,873, entitled “Tissue LigationDevices and Controls Therefor” and filed on Apr. 1, 2010, which waspreviously incorporated by reference, or U.S. patent application Ser.No. 14/195,797, entitled “Tissue Ligation Devices and Methods Therefor”and filed Mar. 3, 2013, the contents of which are hereby incorporated byreference herein in their entirety.

The handle may serve many purposes. Of course, the handle may provide aninterface between the device and the user as the user may hold onto andcontrol the device and its components using the handle. The handle maybe used to control and actuate the snare loop assembly through theelongate body, guide the elongate body, and/or modify the shape of theelongate body using a pull wire controlled through the handle. Thehandle may enable a user to control the release of the suture loop fromthe closure element, and it may be used to house electronic or othercomponents for the visualization tool. The handle may comprise anysuitable elements to facilitate use of the device for the closure oftissue, including sliders, knobs, switches, latches, push buttons, andthe like, which may be coupled to any component of the snare loopassembly to pull, push, open, close, deploy, or otherwise use thecomponent.

In some embodiments, the closure devices described here may comprise atensioning mechanism for managing the tension applied to a portion ofthe suture loop (e.g., a tail of the suture loop) of the closure device.When the closure devices are used to place and tighten a suture looparound a tissue, it may be desirable to manage the tension applied tothe suture as the suture loop is tightened. In some instances, it may bedesirable to limit the maximum tension that is applied to a suture loopat different times during tightening. For example, if a sufficientlylarge tension is applied to the suture loop, the suture loop may cutthrough, shear off, or otherwise damage the ensnared tissue, and/or maybreak or damage one or more components of the closure device.Accordingly, it may be desirable for a user to know how much tension isapplied to the tissue so that the user is able to control and modify theamount of applied force applied to appropriately close the ligatedtissue without damaging it.

In some variations, a tensioning device or mechanism may comprise aforce gauge and may be used to provide a force measurement or otherforce indication to a user during tensioning of a suture loop. Forexample, FIG. 14 depicts a variation of a tensioning mechanism (1400)comprising a handle (1402) and a body (1404). It should be appreciatedthat the handle (1402) and the body (1404) of the tensioning mechanism(1400) may be integrally formed, or they may be formed separately andattached using any suitable means. The body (1404) may comprise a sutureattachment mechanism (1406) and a force indicator (1408). Generally, thesuture attachment mechanism (1406) may grip, hold, or otherwise attachto a suture (1410) of a closure device (not shown). For example, in somevariations, the suture attachment mechanism (1406) may grip, hold, orotherwise attach to a suture fob (1403), which may be fixedly attachedto a tail of the suture (1410). In some instances, the suture attachmentmechanism (1406) may comprise one or more lumens (e.g., two, three,etc.), and a tail of the suture (1410) (with or without a suture fob(1403)) may be fixedly attached to a lumen of the suture attachmentmechanism (1406). A user may pull the handle (1402) of the tensioningmechanism (1400) away from the closure device to apply a tensile forceto the suture (1410). The suture attachment mechanism (1406) may beattached to a force gauge (not shown) housed within the tensioningmechanism (1400), which may measure or otherwise provide an indicationof the tension applied to the suture (1410) via the force indicator(1408). For example, the force indicator (1408) may comprise a pin(1412) and markers (1414) that may indicate the amount of force appliedto the suture (1410).

In some variations, the closure devices may be configured such that thetensioning mechanism may be releasably coupled to the handle of thedevice. For example, FIGS. 15A and 15B show a perspective view and acut-away view respectively of a portion of an illustrative handle (1500)of the closure devices described here. As shown there, the handle (1500)may comprise a track (1502) for a slider (not shown) that may be used tocontrol the closure element and/or the components of the snare loopassembly (not shown). The handle may also comprise an aperture (1504) inits proximal end configured to receive a tensioning mechanism. Thehandle may comprise release slot(s) (1506) extending from the aperture(1504) and at least one lock (1508A, 1508B). The release slot(s) (1506)may be configured to allow passage of the tensioning mechanism pinthrough the handle so that the body of the tensioning mechanism can beadvanced into the handle (1500), as shown in FIGS. 16A and 16B. Thetensioning mechanism may then be rotated such that the pin is placedwithin the lock (1508A, 1508B), thereby rotatably coupling thetensioning mechanism (1400) to the handle (1500). The lock (1508A,1508B) may comprise any element configured to hold the pin of thetensioning mechanism, for example, an indentation, groove, aperture,hook, or the like. The lock (1508A, 1508B) may be located at anysuitable angle with respect to a release slot (1506), for example, 10,20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170,190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320,330, 340, or 350 degrees.

As depicted in FIG. 15B, in some variations, the handle (1500) maycomprise a first lock (1508A) and a second lock (1508B). Here, each lock(1508A, 1508B) is in the form of a cylindrical indentation on aninternal surface of the handle (1500). The first and second locks(1508A, 1508B) may be located 180 degrees from one another and 90degrees from the release slots (1506). The pin of the tensioningmechanism may extend through the tensioning mechanism such that a firstend of the pin rests in the first lock (1508A) and a second end of thepin rests in the second lock (1508B). While both locks are depicted ascylindrical indentations, it should be appreciated that the handle(1500) may comprise locks having different forms. Of course, the handlemay comprise any suitable number of release slots and locks (e.g., one,two, three, four, or more) and need not comprise the same number ofeach.

As mentioned briefly above, FIGS. 16A and 16B depict a perspective viewand a cut-away of a variation of the closure devices described here. Inthis embodiment, the closure device (1600) comprises a tensioningmechanism (1602) releasably coupled to the handle (1610). The body(1614) of the tensioning mechanism (1602) may be disposed within thehandle (1610) of the closure device. The pin (1612) may extend throughthe body (1614) of the tensioning mechanism (1602) and radially outwardsuch that it may rest in the lock (1608). In this way, the tensioningmechanism (1602) may be held in place within the handle (1610) and maybe temporarily coupled to the handle (1610). A user may wish to keep thetensioning mechanism (1602) coupled to the handle (1610) during aprocedure so that the tensioning mechanism (1602) is nearby and readyfor use when the user wants to tighten the suture loop. Once the user isready to tighten the suture loop, the user may rotate the tensioningmechanism (1602) such that the pin (1612) is removed from the lock(1608) and aligned with the release slot(s) (1606). The user may thenpull the tensioning mechanism proximally such that the pin (1612)travels through the release slot(s) (1606) and the tensioningmechanism's body (1614) travels through the aperture in the handle(1610) of the closure device (1600), thereby removing the tensioningmechanism (1602) from the handle (1610). The user may then continue topull the tensioning mechanism (1602) proximally relative to the handle(1610) until a desired amount of force is applied to the suture loop(not shown) and communicated to the user via the force indicator (1616).

II. Methods

The closure devices described here may be useful for closing tissue, forexample, the left atrial appendage. The closure devices may access theleft atrial appendage using percutaneous or surgical techniques, asdescribed in more detail above. When percutaneous techniques areemployed, the closure device may be used with a curved guide device toassist a user in inserting the closure device into a patient's body andaccessing the desired portions of a patient's anatomy. In someinstances, both the elongate body of the closure device and the guidedevice may be curved, and the curvature of the elongate body may or maynot match the curvature of the guide device. When the curvatures of theelongate body and the guide device differ, in some instances, theelongate body may twist or otherwise rotate along its longitudinal axiswhen it is inserted into the guide device. This twisting may cause theelongate body's distal tip, and the closure element, to exit the guidedevice in a different orientation (e.g., at a different angle withrespect to the top of the handle) than when it entered. When theelongate body twists or rotates within the guide device, the distal tipof the elongate body, and the closure element attached thereto, may alsorotate. This may make it more difficult for a user to maneuver thedevice within the body and to ligate tissue.

Thus, it may be desirable for the elongate body to follow the curvatureof the guide device without twisting or rotating within the guidedevice, regardless of whether the curvatures of the elongate body andguide device match when the elongate body is inserted into the guidedevice. This may allow the closure device to advance to the properlocation within the body while the closure element is maintained in auser's desired orientation. Moreover, configuring the elongate body sothat it does not twist or rotate within the guide device may allow theuser to predict the orientation of the closure element once the closureelement and the distal tip of the elongate body exit the guide deviceand properly place the closure element within the body. Furthermore, itmay be desirable to be able to rotate the elongate body a predictableamount using the handle of the device, even when external forces (e.g.,bending forces) are applied to the elongate body (e.g., from thecurvature of the guide device, anatomy of the body, and the like).

The closure devices described here may be configured to be self-aligningor self-orienting when used with (e.g., inserted into or otherwiseadvanced along) a guide device. For example, a user may insert theelongate body into the guide device with the distal tip and closureelement in any orientation, and the distal tip and closure element mayexit the guide device in the same orientation (e.g., with the top of thehandle and the orientation of the closure element aligned), regardlessof whether the curvatures of the elongate body of the closure device andthe guide device are aligned.

FIGS. 17A-17C may more clearly demonstrate this concept. FIGS. 17A-17Cdepict a system (1700) comprising a closure device (1702) in use with aguide device (1704). The closure device (1702) may be any of the closuredevices described above and may comprise an elongate body (1706) with acurvature such that the distal tip of the elongate body (1706) isdisplaced toward the underside the handle (1708) when the elongate bodyis not subjected to any external force. It should be appreciated thatthe elongate body (1706) may have any suitable curvature and it need notbe curved toward the underside of the handle (1708). Furthermore, asused herein, the top of the handle of the closure device generallyrefers to the surface of the handle comprising a control mechanism forthe closure loop, and the underside of the handle generally refers tothe surface opposite the top of the handle. In some embodiments, thecontrol mechanism for the closure loop may be located on a side of thehandle, in which case, the top of the handle refers to the portion ofthe handle facing upwards when a user is holding the handle asinstructed to begin a procedure.

The guide device (1704) may comprise any device used to direct thedistal tip of the elongate body to a specified or desired locationwithin a patient's body, for example, a guide cannula, a trocar, a guiderail, percutaneous tubing, and the like. The guide device (1704) mayhave a curvature along its length and may comprise a lumen configured toreceive the elongate body (1706) of the closure device (1702). To begina procedure, a user may insert the elongate body (1706) into a lumen ofthe guide device (1704), and the guide device may steer or otherwisedirect the distal tip of the elongate body (1706) to a desired locationin the body.

FIGS. 17A and 17C depict configurations of the closure devices describedhere in which the elongate body is configured to resist twisting. Incontrast, FIG. 17B depicts a closure device in which the elongate bodyis not configured to resist twisting, and has in fact twisted within theguide device. In FIG. 17A, the closure device (1702) has been insertedinto the guide device (1704) with the pre-insertion curvature of theelongate body (1706) matching the curvature of the guide device (1704)(e.g., both the distal ends of the elongate body (1706) and the guidedevice (1704) are curved in the same direction, i.e., toward theunderside of the handle (1708)). As shown there, the closure element orloop (1710) has the same orientation with respect to the handle (1708)both before and after it is inserted into the guide device. In someinstances, the orientation of the closure loop (1710) depicted in FIG.17A may be the preferred orientation for the closure loop (1710);however, this need not be the case. For example, in some instances, theclosure loop may have a different orientation.

In FIG. 17C, the closure device (1702) has been inserted into the guidedevice (1704) with the pre-insertion curvature of the elongate body(1706) facing the opposite, or a different, direction than the curvatureof the guide device (1704) (e.g., the distal tip of the elongate body(1706) is curved toward the underside of the handle while the distal tipof the guide device (1704) is curved toward the top of the handle(1708)). Despite the misalignment of the curvatures of the elongate body(1704) and the guide device (1706), the closure loop (1710) has remainedin the same orientation with respect to the handle (1708).

In contrast, in FIG. 17B, the closure device (1702) has been insertedinto the guide device (1704) with the pre-insertion curvature of theelongate body (1706) facing an opposite, or a different, direction thanthe curvature of the guide device (1704). However here, the elongatebody (1706) has twisted inside the guide device (1704) causing theclosure loop (1710) to rotate with respect to the handle (1708). Theconfiguration depicted in FIG. 17B may be undesirable in some instancesbecause the twist in the elongate body may make it more difficult tosteer the device through the body, control the location of the distaltip, deploy the closure loop, and, in embodiments with a suture loop,deploy the suture loop.

As depicted in FIGS. 17A and 17B and described above, the closure loop(1710) may comprise a first configuration in which the closure loop(1710) and the handle (1708) are aligned, and a second configuration inwhich the closure loop (1710) and the handle (1708) are misaligned. Theclosure loop (1710) and the handle (1708) may be aligned when theclosure loop (1710) is in the proper configuration to begin a procedurewhen the handle faces up. The closure loop (1710) and the handle (1708)are misaligned when the closure loop (1710) is rotated with respect tothe top of the handle (1708) such that the closure loop (1710) isrotationally offset from its proper configuration when the top of thehandle is facing up.

The closure device (1702) and the guide device (1704) may comprise adelivery configuration in which the curvatures of the elongate body(1706) of the closure device (1702) and the guide device (1704) aremisaligned (i.e., their curves have different orientations). In somevariations, the closure device (1702) may be configured to remain in thefirst configuration (i.e., with the closure loop and the handlealigned), when the closure device (1702) and the guide device (1704) arein the delivery configuration (e.g., when they are curved in differentdirections). In this way, the closure device (1702) and the guide device(1704) may be configured to be self-orienting or self-aligning.

III. Systems

Described here are systems for closing tissue, for example, a leftatrial appendage. In general, the systems may comprise a closure deviceuseful for performing a left atrial appendage closure procedure,together with one or more additional components. For example, the systemmay comprise a curved guide device comprising a lumen therethrough. Thelumen may be sized and configured to receive an elongate body of aclosure device described here. In some embodiments, the system maycomprise a first guide wire having a size and length adapted foraccessing the left atrial appendage through the vasculature andcomprising an alignment member, a second guide wire having a size and alength adapted for accessing the pericardial space from a subthoracicregion and comprising an alignment member, and a closure device. Thealignment member may be any suitable alignment member. For example, thealignment member may comprise radiopaque or echogenic markers, membersconfigured to produce an audible response, one or more interconnectingmembers, one or more vacuum members, or magnets.

The closure device may be any of the closure devices described above.For example, the closure device may be one comprising an elongate bodywith a first stiffened portion and a second flexible portion, and aclosure element comprising a loop. The system may further comprise anexpandable member or a device comprising an expandable member. Theexpandable member may be any suitable expandable member, such as, forexample, a balloon catheter. The expandable member may have one or moreapertures therein for allowing contrast or other fluids to passtherethrough. The system may further comprise a suture loop, and thesuture loop may or may not be coupled or coupleable to the closuredevice. Of course, the system may comprise instructions for using any,all, or a portion of the system's components (e.g., guide device, firstguide wire, second guide wire, closure device, or some combinationthereof).

Although the foregoing invention has, for the purposes of clarity andunderstanding, been described in some detail by of illustration andexample, it will be apparent that certain changes and modifications maybe practiced, and are intended to fall within the scope of the appendedclaims. Additionally, it should be understood that the components andcharacteristics of the devices described herein may be used in anycombination. The description of certain elements or characteristics withrespect to a specific figure are not intended to be limiting or norshould they be interpreted to suggest that the element cannot be used incombination with any of the other described elements.

What is claimed is:
 1. A device for closing a left atrial appendagecomprising: an elongate body comprising a first lumen, a second lumen,and a third lumen; a closure element comprising a loop defining acontinuous aperture therethrough, a first end of the closure elementslideably disposed in the first lumen and a second end of the closureelement fixedly disposed in the second lumen; and a handle coupled tothe elongate body, wherein the handle comprises an aperture in aproximal end thereof configured to releasably receive a tensioningmechanism, a release slot extending from the aperture, and a lockconfigured to hold the tensioning mechanism when the tensioningmechanism is received in the aperture.
 2. The device of claim 1 furthercomprising the tensioning mechanism positioned within the aperture. 3.The device of claim 2 wherein the tensioning mechanism is rotatablycoupled to the handle.
 4. The device of claim 2 wherein the closuredevice further comprises a suture loop, and wherein the tensioningmechanism is configured to close the suture loop around tissue after itis released from the handle.
 5. The device of claim 2 wherein thetensioning mechanism locks into the handle.
 6. The device of claim 2,the tensioning mechanism further comprising a pin, wherein the pin isplaced within the lock when the tensioning mechanism is rotated.
 7. Thedevice of claim 1 further comprising at least one of a scope, a light,and a camera.
 8. The device of claim 1 wherein the device is configuredto close a left atrial appendage during an open surgical procedure. 9.The device of claim 8 wherein the open surgical procedure is a mediansternotomy, mini sternotomy, thoracotomy, or a thoracoscopy.
 10. Thedevice of claim 1, further comprising a malleable member fixedlyattached to the elongate body, wherein the malleable member isconfigured to retain a curve after a force is applied, and whereinapplying a force to the malleable member modifies a curvature of theelongate body.
 11. The device of claim 10 wherein the malleable memberis disposed in the third lumen.
 12. The device of claim 11 wherein themalleable member comprises a first end and a second end, and wherein thefirst end is fixedly attached to a proximal end of the third lumen andthe second end is fixedly attached to a distal end of the third lumen.13. The device of claim 12 wherein the malleable member comprises anannealed stainless steel wire.
 14. The device of claim 10 wherein themalleable member comprises a jacket around the elongate body.
 15. Thedevice of claim 14 wherein the device further comprises a pull wiredisposed in the third lumen, wherein the pull wire is configured todeflect a distal end of the elongate body.
 16. The device of claim 14wherein the jacket is annealed stainless steel.
 17. The device of claim16 wherein the jacket comprises a spiral cut pattern.
 18. The device ofclaim 1, wherein the lock is on an internal surface of the handle. 19.The device of claim 18, wherein the lock is in the form of a cylindricalindentation on the internal surface of the handle.
 20. A device forclosing a left atrial appendage comprising: an elongate body comprisinga first lumen, a second lumen, and a third lumen; a closure elementcomprising a loop defining a continuous aperture therethrough, a firstend of the closure element slideably disposed in the first lumen and asecond end of the closure element fixedly disposed in the second lumen;a handle coupled to the elongate body; and a tensioning devicecomprising a pin, wherein the tensioning device is releasably coupled tothe handle, wherein the handle comprises an aperture in a proximal endthereof, a release slot extending from the aperture, and a lock, andwherein the aperture is configured to releasably receive the tensioningdevice and the release slot is configured to allow passage of the pinthrough the handle.